Pros:

- Some good ideas such as the light switches or the zombie incinerator

Cons:

- Horribly stretched textures
- Awful aesthetics
- Buggy navigation
- Zombies and special infected spawning in your face for no reason
- Barely playable, let alone enjoyable

Conclusion:

At the beginning of the campaign I was greeted by a Death Toll camera looking at the abyss and then flying backwards through geometry. Then I was greeted by the horrid, ugly ground texture on which one pixel stretched a meter, and the supposedly outdoors setting was walled in by the same repeating boulder models and mostly nothing else. The sizes and proportions of all the brushwork was completely messed up and barely anything looked like something you would find in real life. The world was mostly made up of boxes with horribly stretched textures that were mostly out of proportion and made no sense what so ever.
The forced spawns were horribly broken, not once did I have zombies just spawn all around me out of nothing, and the same goes for special infected spawns. This made parts of the campaign relentlessly difficult and punishing. The navigation mesh barely works.
By the last map it looks like the author has completely given up; It was nothing more than giant box hallways with the occasional shelf prop tucked in, while the finale didn't even work and neither did the ending once we did manage to force start it using cheats.

Overall, the whole campaign looks like it was made by someone who barely knew what they were doing and just threw random crap in everywhere. It looks horrible and it plays horrible, I have no clue how someone could give this out of their hands as a serious, finished product. I give this campaign a generous 1.3 because it had some novel ideas going for it, but I suggest the author improve his or her work by a metric ton before releasing another campaign.

Pros:

-L4D zombies in ravenholm
-Excellend capturing of the Half-Life 2 unvirese
-Good style
-The finale was really stylish and nostalgic
-Maps were good length
-Excellent conversion of certain actions into panic events

Cons:

-Ravenholm from Half-Life 2 was ported, but nothing really interesting was added
-A tad confusing for those who haven't played Half-Life 2

Conclusion:

An awesome port of Ravenholm, creatively titled, greatl packaged. If you wanted to play Half-Life 2 with Left 4 Dead's infected zombies, then try this out, if you just want a nice campaign to spend an afternoon with, then try this out. Honestly, i don't see a reason why anyone who is looking for a custom campaign shouldn't give this campaign a try, with the small file size you really have nothing to lose.

Pros:

-Overall great looks
-Defend a McDonald's restaurant
-Creative secret to give you extra supplies
-The ufo appearing when you reach 10 minutes was a nice idea
-Nice custom textures
-Good feeling and overall fun
-A parody of a Guns N' Roses song

Cons:

-Not very hard
-The "safe room" door can be glitched
-Overall a small moving space
-Considering it's a survival map, there aren't many graphical details

Conclusion:

A fun survival map that you can sure spend a few attempts on getting 10 minutes on, although it's not that hard, easy to figure out where to hold out best since it's not a very large map. Not perfect, but there is not much room to improve either. If you like survival maps with a nice feeling, then give this a try. However if you're not into survival, then don't expect this to revolutionaize the game mode.

Pros:

-Somewhat a nostalgic atmosphere
-Great level design altogether
-It has a stranded feeling to it
-One good panic event idea

Cons:

-Nothing special to the campaign really
-The constant hordes were annoying
-The finale was illogical(call the metro with a ticket machine? not to mention that ticket machine could we walked right trough)
-Levels were too long
-Most of the panic events were absolutely uncreative, almost all of them consisted of opening a door with a switch.

Conclusion:

It's a yet-another-custom-campaign, but it's also much more than that, it's overall really fun and you can sure kill a few afternoons on it if you have 3 other friends. If you don't mind the long levels(especially the final map) and the repetitive panic events then definitely give this a try, but if you're looking for something really unique then you should look elsewhere.

Pros:

-Great atmosphere
-Unique design
-Overall fun with friends
-Creative finale ideas
-Storytelling via readable notes
-Extra task for the finale

Cons:

-Some areas were bland
-Mostly only environmental lighting, which means a lack of visual cues, sometimes making it very hard to find out where to go.
-The readable notes appear for everyone even when only one person reads them , which can be quite annoying
-Not really a con, but even though the evac tells you to blow up the bridge to prevent acces for the infected, the infected come mostly from everywhere but the bridge.

Conclusion:

A fun campaign, lots of good ideas especially with the finale and some panic events, however it gets dull at some parts.
But this won't stop this campaign from being overall really fun, anyone who likes a campaign with a few unique ideas thrown in it should definitely try this out.

Pros:

-Good style and atmosphere
-Good detail
-Some very creative panic event/safe room designs
-Transition between environments, urban to rural
-The finale was really fun

Cons:

-Nothing really unique
-Forgettable atmosphere
-Finale map a tad too long
-Despite good effort at some parts, other parts seem really bland.

Conclusion:

The novelty value is difficult to explain, it almost feels like just-another-campaign, but it still stands up to the quality and even throws in some great ideas, so it's a pity that even though the atmosphere is great, it somehow fails to stand out.
One is sure to have fun and will definitely praise the campaign, but after not playing it for quite a time, i'd doubt anyone would instantly recognize the campaign again.

I'd say you can fix this though, by giving the campaign a graphical overhaul and a unique color scheme. Believe me, that will add to the novelty value a lot!

Pros:

-Fun spinoff of the Crash Course campaign's name
-Crash Bandicoot's universe meets Left 4 Dead's
-Fun ideas, great level design
-Lots of custom content and fun things
-Wall writings in the style of Left 4 Dead but written in topic of the game

Cons:

-Sometimes confusing, but perhaps only for people who haven't played Crash Bandicoot.
-The run after defeating the final boss was asking way too much considering the probable state of the survivors after the boss fight.

Conclusion:

A great campaign based off another game, really fun, anyone who remotely likes platformers should definitely give it a try, although those not familiar with Crash Bandicoot will need to dedicate some trial and error figuring out what each element does in the campaign.

Pros:

-The first level's first part was really well made
-Overall fun
-Lots of cool ideas(for example the surprise slide, i loved it!)

Cons:

-Way too confusing
-The first panic event is way hard with the infected spawning underwater
-Some brushwork is downright disgusting
-Gets bland and boring in the long run, especially when playing alone

Conclusion:

The overall idea is great, it sounds really good on paper, but the execution is lacking. The creator should definitely improve on his brushwork, and place visual cues amongst other things to help the players understand what they're supposed to do.
If you like getting lost and figuring out what you're supposed to do and where to go next and don't mind the sloppy graphics, then definitely try this out, but if you're more into classic straightforward maps, then you can give it a pass.

Pros:

-Unique style
-Changing time of day in maps
-Changing environment (rural to city)
-Some good panic event ideas
-Amazing custom content
-Automatic panic event that can catch you off guard and surprise you

Cons:

-A bit hard, even on Advanced
-Some maps are a tad too long
-The automatic panic event isn't that surprising for the second time. Perhaps you should vary its position each time the map is loaded.
-Some geometry is not very detailed
-Although not very distracting, some visual cues point to useless areas.

Conclusion:

Definitely a must try. The demo was fun and i'm really looking forward the final product. There is obviously a lot of work being put into this. There's plenty to set this campaign apart from the competition, however on second playtrough they may not seem that effective.

Pros:

-Really good unique style and atmosphere
-Creative layout, fun for versus
-Creative events(panic and otherwise)

Cons:

-A tad confusing
-Bots screw around sometimes
-The tarp at the finale has a bugged animation(You should make it reset the animation before it starts flying off)

Conclusion:

Overall, a very good campaign. It has a consistent and unique atmosphir, and looks overall great. Although the environment could use some variety, it has become dull after a while and it caused me to get lost a few times as well.
Definitely a must try, there was a lot of work put into this, but it's not perfect. It could be, but it's not.

Pros:

-Random/free choice paths
-Great Attention to detail and immersion
-Even the misc. rooms are greatly detailed
-Unique panic and scripted events
-Custom writings on the wall, i loved those
-A cool reward for finishing the campaign
-A unique and memorable atmosphere
-Small file size considering the amount of goodness it's packed with

Cons:

-The bugs mentioned by others(getting stuck near the helicopter mainly) are really annoying and can screw up quite a lot of versus games.
-Lots of extra things you have to do in order to get the campaign fully working, although that is rather Valve's fault, so this won't affect my rating.

Conclusion:

This is a great campaign and much more work and effort went into every single detail and it should be respected. The atmosphere is unique and unlike any other campaign, custom or official, and remains memorable all the way. I've seen way too many campaigns that i finish halfway trough and forget the name of the campaign i'm playing.
But not this one, this campaign sets the new standard of how campaigns should be done, to both Valve and the modding community.

Let me finish by stating how much i honour your commitment to Left 4 Dead. I see way too many otherwise talented mappers just give up on L4D and continue to update/develop their complete or new campaigns for L4D2. It makes me happy to see that quite a few people went back to L4D to play this campaign at its best. You've done a great deal to keep this game alive, and that's saying something big, considering what Valve is doing to L4D. 
I'm really looking forward to seeing more campaigns from you.