Pros:

Single Player - Pinkie Pie with a Frying Pan
*Fits very well, and uses a non-pinkamena version. 

Campaign/Realism - Pinkie/Rarity/Twilight/Dash
*Aside that it looks a little over crowded, appropriate usage of the 4 motif and well drawn. 

Mutation - Discord
Creepy as hell look, but it serves its purpose as god of chaos and the theme of Mutation.

Versus/Realism Versus - Dash vs Applejack
Love the use of the pose and characters. Also gains relevance that there is now a Eppaljeck mod on the site. 

Scavange - Rarity's hoof grabbing a gas scan.
Simple. 

In General:
All hand drawn, which is a bonus, and pretty well drawn as well. 

Cons:

Still Waiting on Survival
*would love to see it as Fluttershy surrounded by the sillioutes of the infected, but that's just me. 

Because PC will not support co-op without mods, nothing planned for that either. Tis sad.

Conclusion:

Some may have an issue with the repeated images, but I really love the way this is coming. Your art is good and the usage in the main (mane) menu is appropriate. 

Pros:

*A great mod, makes surviving with bots more fun, especially on harder difficulties (as they aren't bloody useless). 
*Bots using melee helps during gauntlets.
*Allowing players to die and the game continue really help during those BS moments in singleplayer

Cons:

*Handling of special infected is iffy
**Sometimes, they will destroy a Special Infected (Smokers mostly it seems) before the scripts are even aware (Ie, calling it out).
**They seem to be less adept handling Jockeys (had an issue where a Mechette Rochelle was following a jockey riding me, rather then switching weapons to deal with it)
*Sometimes bots will stand there like wooden ducks with their melee out rather then switching to the primary to deal with common.
*While I prefer magnum, if a Magnum bot (Ro or Nick) both grab melee's, the others (Ellis and Coach) will still both dual wield pistols rather then one taking a magnum role to balance out.
**The reverse is also true
*Bot Ellis and Francis seem to still treat the Hunting Rifle and Sniper Rifle as the same Teir, even though the Sniper is much more efficient. 
*Sometimes, bots that lead will skip crescendo events by teleporting through them. Its not as bad as before, mind, but I had an issue where Bill teleported through No Mercy-Chapter 2 and took sniper position on the floor above before the door was open. [Seems to always be that map, as the version before your update, all 3 teleported through it and could have finished the level]

Conclusion:

Aside from the last Con, I really do love this. It makes the game more interesting by making the bots more supportive and offensive. 

Pros:

Soundfile when killing zombies.
Nice Pink Skin (I like pink, can't you tell)
Katana appears in the campaigns I play the most, so I get a lot of use out of it
Best Pony

Cons:

None

Conclusion:

I will say that I did NOT read that this thing had a soundfile when first downloading it. I heard the giggling, but it was so fainted that it actually startled me. Wasn't until I was using it in a horde that I figured exactly what was going on. 

That aside, AWESOME SKIN! <3

Pros:

Nice textures applied to the gun
*I hate saying things are brony and non-brony, yet this rifle can fit into both slots, because there is no clear evidence of ponies for those who are not bronies (aside from card 1, which doesn't matter in game)
Looks even cooler with custom animations
I love the swirl in the scope

Cons:

None, previous con redacted.

Conclusion:

Its a pretty awesome texture, and I do like the fact it's "stealthy". Even better, its not really a pony mod. Ponies != Zebras x3

Pros:

Fun Little Hud Mod

Cons:

My only problem is derpy being used twice (i know the two images these come from, so, I don't blame you)
No change to names but still alright.

Conclusion:

Really love the images. The first one where Trixie is put in the proper place. Also, do like background characters that were used for wallpapers were used for the HUD.

Pros:

Like the colors
Tara Strong's probably going to freak if she sees this.
Love the little decal below the iron sight

Cons:

None

Conclusion:

Its a skin, simple, but I enjoy it. I do like the handle's accent stripe and the text. Its just a fun little auto shotty to use :D

Pros:

Awesome green flames and cyan-faded decals along the gun
Very glossy blackness everywhere
Love the little "Property of Queen Chrysalis" on the side. 
Kept that little dial scope on the top (never really knew what they are used for, but I still liked seeing it)
The face on the scope, looks particularly menacing . (It also looks very awesome during the chapter change, when it grays and blurs out)

Cons:

The minor issue mentioned earlier has been fixed, so this area is intentionally left blank..... damnit.

Conclusion:

This entire sniper rifle just SCREAMS detail and effort, and every bit shows. Not only that, but helping with that minor issue I was experiencing just showed more effort into making an awesome skin that everypony could use. 

Added to the fact that I used Arby26's military sniper animations and MW2 Sound effects make this rifle all the more bad ass to use. I find myself taking the roll of Sniper more often thanks to this skin. 

Pony version or No-Pony Version, this skin is amazing and worth of the constant 10's it receives. 

Pros:

20% Cooler Colors
Grit, Scratches, Engraving (NLR, Luna <3), and even a bandage on the handle makes it look like the gun has been places. [Added to valves original twistie ties holding the flashlight make it looks all the more realistic in the L4D Universe.]

Cons:

A Con? Is that like a Convention? What does that have to do with this awesome AK?

Conclusion:

I really like this skin, when you can hardly tell is a brony-related skin in first person. (Unless your view models are drawn larger). Its a very well done skin, and even better with different animations and sound effect. The AK has always been my favorite in the vanilla version of L4D2, and now its getting even more use.

Guess it really proves that something designed for a certain audience can also appeal to people outside its target demographic. 

Pros:

Colorful pan
Blood Splatter effect makes it look silly
Makes the frying pan more noticeable and now one my favorite weapons. 

Cons:

*As with Sabre's Pinkie Axe, there is a strange bug that makes coach grunt each time the axe is swung, regardless of character. (It is EXTREMELY off putting to hear zoey grunt like an old black man). 

Conclusion:

Despite the con (because it existed with the Axe mod as well), its a great skin. 

Somepony is going to have a headache after this.

Pros:

*One of those Subtle skins that you download, sometimes forget you downloaded until you actually glimpse at it and get fuzzy feelings for it.
*Really do like the illuminated Ditzy/Derpy on the screen

Cons:

*Its washed out colors make it blend a little with environmental, until the glow takes over. 

Conclusion:

Again, cute and subtle. A worthy download.

Pros:

*Funny Slogan
*A good use of Celestia
*Reminds me a lot of one of Frank West's Super Moves from UMvC3. 

Cons:

*A little too solid, though it is cartoony so I let it slide, but others might not be that forgiving.
*There is an odd Gold, reflective thing on the tip of the bad that seems to only be there in 3rd person. Edit: I know its the crown, but it seems to reflective, compared to the other part of the bat.

Conclusion:

I like it, because not only does it remind me of ponies, but it reminds me of Frank West and the other Zombie killing game. :D

Pros:

*Really well designed campaign
*Ambient Music is really Creepy
*Depending on Difficulty, T2 Weapons can be found from the first to third chapter, making it all the more decisive
*Multiple paths that the AI Director doesn't control, letting players decide (in any gamemode) which way is more perilous. 
*Exploration is rewarded.
*Chapter 4 is really disorienting with the constant tilt of the ship.
*Finale is made easier in L4D2 with addition of Biles and Melee. 

Cons:

*There is ZERO custom dialog. The Survivors are eerily quiet which takes away from the replay factor.  
*Daylight is alright, but the ambient music seems to be more fit for the old 'night' setting. 
*The Sewer Crescendo event is overly complicated. There is NOTHING inside the map that indicates what to do, so I assumed it was a bug until I was about to write a review earlier. A better suggestion would be to do what is done in Dead Center's mall: an event that can be activated at two different locations.
*Its a basic port
**The events are too easy with new weapons, and for some reason there is a lack of special infected even on Advance. 
**Daylight made the witches have always been easier to deal with; but in this campaign, they are no threat with the ability to take a route they aren't on. 
**In the Sewer of Chapter 3, the water (a foot of it) slows you down if you walk on the middle and doesn't if you walk on the sides.
*A complete lack of Graffiti, even ones that already exist in the game files. 
*While I never beat the original finale, I always assumed it was a boat rescue, and while I love the idea of being rescued by a Pinkie Pie Balloon, it seems that the Survivors could not know that they could be rescued that way unless told in the campaign somehow. 
*The finale still has the problem of tanks blocking the pathway if you attempt to hold up at the lighthouse. 
**First time playing it, there is no way of telling where the balloon is going to be. 

Conclusion:

Death Aboard was my favorite custom campaign in L4D, yet the port seems to suffer in a lot of areas. While its still fun to play, most special infected threats are defanged. Even playing Hard Eight, there were very few times when the infected became too much of a threat. 

Its still a fun map, despite its flaws. 

Pros:

Love the Bright Blue skin, stands out.
The Slogan is funny.

Cons:

This only replaces "Red" gas cans. The orange ones from Scavenge remain untouched.

Conclusion:

Oh ho. Will those Crusaders ever find their special talent and earn their cutie marks?

Whatever their outcome, I enjoy their antics, and our antics with their gas cans.

Pros:

*Slightly asymmetric
*Walking animation FINALLY
*Different (and IMHO, better) reload and withdrawal animations
*Original sounds still fit.
*Hey look, a bullet casing is ejected when you fire either one.

Cons:

*They seem a little closer together then they should. But I don't know about guns in the first place, so its not too much of a big deal.

Conclusion:

I don't care how many updates or changes valve would make to the original pistols (The P220 and Glock), but no matter what, I never did like them. Sure, I understand why they were chosen (to be more realistic), but so many things about them bothered me. They felt extremely weak compared to the L4D1 pistols, and the lack of walking animation seemed so much of a breaker from using them, almost like you are hovering the entire time. Not to mention the whole the mismatch issue when picking up one side arm and getting another (or both). 

With that much wrong about the original pistols, I am glad there are changes like this. Because of those pros, i have started using the pistols over the magnum or melees. Strange that some minor visual problems can make or break an items use for gamers. 

Pros:

*Professional Layout (you'd swear its a valve map). Everything to weapon layout and body placement simply screams a hidden story of Survivors past
*Reused and new graffiti
*A variety of locals visited
*Interesting new crescendo events
*The 4th to 5th level saferoom was amazingly well done
*Interesting way of fitting survivor lines for certain situations.
*Run n Gun finale that leads to a stationary Tank fight.

Cons:

*The layout can be slightly confusing. Not too bad (you won't go down a completely wrong path and have to backtrack too far)
*The Police Station crescendo (picture 3) was confusing. The tool tip looked like it was still on the first floor, while it was still on the second. So I wandered around the first floor until I figured I'd try upstairs.
*Seems like the some of the miniguns and heavy machine guns have little use. But then, that may be for Survival mode. 
*For some reason, all vocalization commands and responses go quiet after the finale begins. No infected calls, no cries for help, no identification of weapons. [except for when the barrier goes down and from Soldier 2]
*Bots have trouble getting onto Crazy Ron's train to start the crescendo or staying on once it starts moving. 

Conclusion:

Despite my cons, they are minor nitpicks. I think this is an amazingly designed campaign (how could it not be, its featured most of the time on the L4Dwikia). Personally, I think this should be an official campaign just as much as Cold Stream should be. Just an awesome map in general, one should have it in their campaign selection. 

Pros:

Washed out colors, scratches, dings and marks make it look all the more fitting.
Its my favorite melee weapon, and now has pinkie pie on it
Its in every (or mostly every) campaign
Level of detail depends on your graphic settings, making it just as cool as the regular axe

Cons:

Cupcake references. 

Conclusion:

in truth,  would see an axe as more Applejack's thing, unless we are counting the a'fore mentioned con (let hope not). 

I love the axe as well as Pinkie Pie :D

Pros:

Bright and colorful guitar.
Very good complimenting colors
The red from blood splatter also complements it well.

Cons:

Some of the text (Fluttershy) on the back is too difficult to read.

Conclusion:

Because you asked :3

Pros:

Readds some of the ambient music

Cons:

Missing quite a few tracks (safe room audio does not play)
Still uses L4D2 incap, death, monsterswithout
BIG error during the finale: the ambient (before you summon the horde) music will always play. When I called for Rescue 7, no "Rescue is coming, prepare yourself" music played, no horde music, and when stepping outside to relocate to the barn, the same ambient prehorde music played, despite being chased by fleasheaters. 

Conclusion:

Its a step in the right direction. It DOES contain the starting music, but valve I think readded that anyway, without the need for the mod. Still, the Ambient "quiet" sounds as you progress through the campaign is enough to at least meet this half way. 

Pros:

Unlike your other Pony skins, which are bright and colorful, this fits the L4D style by being Dark while still being just as awesome
DJ-Pon3 all the way
This really looks awesome how it slightly glows in the Tunnel of Love
It only gets better with Blood Splatter

Cons:

Insert witty "con?" dialog here [EG: KAHN!]

Conclusion:

First skin I downloaded, and proud to convert me. Not into a brony, but that ponies can fit into L4D. Quite an awesome skin, I just wish it wasn't ONLY in DC and the Parish.

Pros:

Its Pinkie Pie Party Rifle
Love  the cutie mark on the side and pinkie's face on the clip.
Its definitely got an interesting color scheme. 
Makes the Assault Rifle my new favorite over the AK47 (until someone makes an Applejack mod of it)

Cons:

I can't explain why this is a con or why it bugs me, but in the world view, it just seems smaller. [in your pictures it looks fine, so I don't know what I derped] 

Conclusion:

Awesome Rifle is awesome. 

Pros:

Makes Francis a more silly character, in a good way of course.
It fits his character, having "borrowed" it.
Having not modified his tattoo's, facial appearance and gloves add more to how awesome Francis is. 
Keeps the clothes during the passing finale. 

Cons:

Francis's old clothes reappear in "The Passing" introduction.
Does not help me avoid the Death Toll Church guy event. He still doesn't think Francis is a Cop.

Conclusion:

A pretty awesome mod if I do say so myself. Quite the character Francis, I don't doubt he would have one of these, even if the badge is something you get off one of those toy deputy wallets. 

Pros:

Its of Pinkie Pie
Its quite colorful
I like the Woo sound effect

Cons:

*I think the Woo needs to be quite louder. Its so soft compared to the beeping of the original that it is hard to tell when one is thrown. I walked into a couple because I didn't hear it over the sound of the fighting. 

Conclusion:

A Decent Pipe bomb skin, adds to the sillyness of all your other skins, but this one could be improved a bit.

As Fury state, I expected a silly kind of particle effect, like balloons or confetti, but an explosion of corpses is fine too :D

Pros:

*The Cool Colors fit very well against both the Brightness of "Dead Center" as well as the dark areas of "The Passing" and "Dark Carnival"
*I love that the Sponsor logos are still on the front.
*The modification of the Banners around the Car in Dead Center were a very nice touch (I didn't think they were going to be in the pack, to be honest).

Cons:

*"Don't go to bed" image on the back gives me a weird vibe.
*If you were able to change the banners around the Jimmy Gibs Jr, could you also change the Jimmy Gibs Posters around the Mall campaign to show the modded Luna Race Car? 

Conclusion:

Very interesting Modification, of all the things that COULD be modified, I didn't realize the Jimmy Gibs Jr. could be, or even would be, one of them. 

I like it and feel ever more proud to have a MLP Themed Ellis gas up the Jimmy Gibs Junior. 

Pros:

Re-adds the tension during the horde fights, healing up in the safe room and panic events.
With A modified talker mod, the characters and music make me feel like I am playing L4D1 again with new weapons.

Cons:

Minor issue where the L4D2 death music and L4D1 Death music played at the same time. However, it happened only once and since then hasn't happened again. 
Its a shame these can't be used on Official Servers. 

Conclusion:

I never noticed how Bland the campaigns were without music, especially the "germ" sounds. Its why I hardly played any of the re-release beta maps. Thanks for adding the music back. Hopefully valve will add them back on their own soon, but until then, all 3 of your sound mods (Blood Harvest. Dead Air, Death Toll) are something every L4D2 player should have installed :D

Pros:

*Makes L4D2 more replayable, just to hear the conversations.
*Cut Dialog fits well
*Changed Dialog triggers make the characters more interactive with each other; thus adding to that overarching story Valve put in.
*I am beginning to like Rochelle from her newly included lines. A feat I thought impossible.

Cons:

*Minor cut offs between dialogs originally included and added by the Modifier
[Examples: Giving a sigh of relief and thanking someone for being healed, or screaming in pain and asking for help when incapped]
*Sometimes, Subtitles do not appear. This may not have anything to do with your modifier though, as some of the cut Dialog wasn't given a subtitle. Either way, I just wanted to point it out for anyone reading. 

Conclusion:

This mod does what L4D2 was suppose to be about: Replayable Zombie Apocalypse. A very good mod that is definitely worth a download. 

Pros:

Bright and colorful, so it stands out a little more.

Cons:

None.

Conclusion:

Its just a weapon skin. Its silly, but I like using it.

Pros:

Ponies and Ellis, someone finally did it.
Makes Ellis stand out in darker areas.

Cons:

Just curious as to why Rainbow Dash is a scout on the front. [He loves TF2, as he says, but still...]

Conclusion:

Because MLP is gaining popularity, a simple reskin seems to make the character more like someone you would come across in real life. Not to mention, its totally plausible seeing Ellis be a brony. 

I do play Ellis often, so I can really only see it when someone else or in the SI's grasp. Still, I'd play as Coach or Nick just to see Ellis walk around with this shirt.