Pros:

A new look for the Spitter. Looks good. 
GREAT to use in urban settings or L4D1 campaigns. 

Cons:

Something is just 'off' about the fishnets.

Conclusion:

Very good Spitter mod that makes it a more 'urban' look, and it fits better for campaigns like No Mercy or Dead Air.

Pros:

Creepy!
Can fit both the L4D2 and L4D1 campaigns well. Works for both Urban and Rural Settings.

Cons:

None. My favorite jockey mod and one I think I will leave permanently on.

Conclusion:

One of the best, if not the best, jockey mods IMHO.

Pros:

Looks great.
Fits the Jockey Well.
Especially good for a more 'urban, northern' style to go with the L4D1 campaigns. (Always thought the l4D2 special infected looked a little out of place)

Cons:

None that I can think of.

Conclusion:

Great replacement for the Jockey and it really works with the character.

Pros:

Zoey in a mini skirt. :)
Regular zoey hair and face. :)
Plays great!

Cons:

Nut N'Honey

Conclusion:

Fantastic. This is a mod I have permanently turned on! Perfection!

Pros:

Rorscahch from Watchmen! Real cool.
Good textures.
Face blob move, not perfect but still looks good.
Hands and down-pictures. Portrait too.

Cons:

Blobs all but disappear when flashlight is on his face.

Conclusion:

Real cool character replacement.

Pros:

Looks good and adds color. 
Dig the logo.

Cons:

None. I like it.

Conclusion:

Solid chainsaw mod. Adds a nice flavor to the chainsaw. :)

Pros:

I love NBC!
Looks great!
Plays very well.
Weapon hand animations and they look great too!

Cons:

It replaces Coach, my favorite l4D2 character. :( 
Would have preferred an Nick or Ellis replacement, but that's just because I like Coach.

Conclusion:

Great character mod. Bravo!

Pros:

Looks great.
Weapon Hands.
Portrait and down poses.

Cons:

No facial animations.

Conclusion:

Very good. If this had facial animations would have been rated even higher. 

Pros:

Great portraits.
Very colorful.

Cons:

I would have went with a dark purple for Coach but that's just me being picky.

Conclusion:

Outstanding mod that add color and flavor to the game. Go for it.

Pros:

Creative level design.
Unique type of building for the finale.
Use of cliffs and gorges work well here.

Cons:

The water plant / mill area can get confusing. I got lost and took a long time to figure it out.

Conclusion:

It's no Suicide Blitz 2 or Dark Blood 2, but it's a worthy addition to any L4D fan. Take the leap!

Pros:

Beautiful, just beautiful level design. 
Dark and forbidding tone.
Choice of paths!
The 'failed' helicopter rescue. Great touch.

Cons:

None.

Conclusion:

A perfect example of a top custom map / campaign. This is a must download for and L4D fan.

Pros:

Excellent atmosphere. You can almost feel the bitter cold.
Challenging.

Cons:

It's a bit cluttered and claustrophobic.

Conclusion:

Nice little survival map. 

Pros:

Crash course on steroids! 
Military zombies imported from L4D1. BIG PLUS for this! :)
Use of water effects.
Great gameplay.
Very challenging.

UPDATE: "Allison" graffiti has been restored in the start of Map 2. Now Coach can laugh at it. :)

A more fair challenge with the update.

Cons:

An intro for Map 2? Not necessary but it's kinda grown on me.

Conclusion:

Best version of Crash Course for L4D2 you can get.  Even better with the updates.

Pros:

The first and third maps. The Foundry level is epic!

Lots of action.

VERY challenging.

Cons:

The second level...what is this a secret place 2000 feet underground? Interesting but that staircase gets tedious fast.

Long load times.

Final map didn't really make any sense or have a logical presentation. Was like just throw in a few random buildings together like a lego city.

Conclusion:

Doesn't quite reach the top leagues as Suicide Blitz, Dark Blood 2, or I Hate Mountains, but lots of fun and VERY challenging. 

Pros:

Great level design. The first level is particularly spooky, especially that house with a creepy version of 'Unchained Melody"

Good flow.
Great Starting Area.

A Motel, sewer, river, and a funeral parlor in one map?! Sweet!

Loved the train part.

The car alarm rush was also a rush.

Cons:

Finale could have been a little better. But just a small nitpick.

Conclusion:

Excellent. This should be downloaded by any serious or even casual L4D fan. Even more fun if you use a custom mod to mix and match your favorite L4D1 and L4D2 survivors!  Coach, Zoey, Ellis, and Louis for me. :)

Pros:

Very good level design.
Good voice clips.
Good sky box...but..(See cons)

Cons:

Sky box flickered on and off for me.
Panic event to open the safe room got a little tedious.
Bots didn't trigger the car escape for a while when the car was ready.

Conclusion:

Solid campaign and a worthy download for any L4D fan. I'm  curious if the voice work is from the game or if the original voice actors did voice work for the campaign (which would be awesome!)

Pros:

It's Death Toll!
I LOVE Death Toll!
It's my favorite L4D1 campaign.
Plays nearly exactly like it.
Colors exact and consistent unlike the Dead Air and Blood Harvest conversions.
Oh and the water added in the first map is a great touch.

Cons:

Missed the church guy. :(

Conclusion:

My favorite L4D1 campaign in L4D2. What's not to like. :)

Pros:

Good consistent location.
Clever level design.
Some may dislike the overall 'gray/monochrome/ look of the campaign but I think it's great. Very moody and forbidding.
The bridge panic event was a fresh approach to panic events.
Crazy finale that really kept the pressure on in the race to the top.

Cons:

The Tank can instant kill if he punches you out of the building in the finale.

Conclusion:

This reaches the high quality of  Dark Blood 2 and Suicide Blitz 2 among the top campaigns for me. Great Job. This would be worthy of inclusion in an official Valve sequel. 

Pros:

The Set Design! Oozes of quality!  
Creepy atmosphere.
Use of "Hard Rain" effects. Always enjoy the rain.
Great level work.

Cons:

Finale is hard especially with bots. 

Conclusion:

One of my all time favorites! <:)

Wish I knew how to upload a screen shot of my dream team playing it here.