Pros:

- the game didn't crash for me :)
- functional AI navigation with no problem except the final escape
- a variety of environments, and i enjoyed playing on the rooftops
- solid gameplay with no noticeable bugs

Cons:

- as others noted, the rescue vehicle did not move during escape
- the water area and the rescue vehicle were a bit glitchy, easy to get trapped
- afraid to say that the map design doesn't feel very original, like a mix of valve campaigns

Conclusion:

It was a smooth playthrough, but I must admit that I did get bored on a couple of occasions. The maps are well designed but do feel generic. I am glad the finale didn't crash as others noted!

Pros:

First of all, this is easily the best custom campaign I've played. The finale puts a huge smile on my face. It's an awesome treat for those who are familiar with the movie, and for a campaign inspired by it, there can't be a more fitting grand finale. 

- phenomenal AI path-finding, except for one instance noted in cons
- fantastic lighting and atmosphere
- great idea to encourage players to use pistols only in the beginning
- timely placement of supplies
- extremely detailed and beautiful environments
- no trouble at all for AI friends to gather in elevators
- exciting gameplay throughout
- perfect length
- thoughtful graffiti that i'd be hoping to read more in details in my next playthrough 
- smart secondary reference that i didn't think of until reading the explanation

Cons:

In map 5, my AI friends have trouble going down the ladder. This appears to be only problematic for the L4D2 version, at least for me.

Conclusion:

Thank you for making this, Kev! It's awesome to play through a campaign made by someone who appreciates fine cinema. This is a campaign I will play over and over again.

Pros:

- the lighting is truly as fantastic as noted by others
- the transition from claustrophobic underground to open surface area is thrilling
- timely placement of hunting rifle
- crazy explosive barrels
- awesome shotgun placement in the finale
- great idea and execution for summoning rescue
- not much problem with AI, except for what's noted in cons

Cons:

- somewhat strange lighting on the bridge with cars, which can be a problem with my graphic setting
- as others mentioned, the rescue vehicle does not move away in the outro
- the water and background vista in the finale look incomplete
- if you get incapacitated hanging off ledges from the water in the finale, it's extremely difficult for AI bots to save you, and impossible if hanging at the edge of the rescue vehicle

Conclusion:

This is a wonderful campaign. Thanks for making this. Most of the imperfections are with the finale, which looks like it could be polished further. I have no problem with the length, and I like the idea and contrast between the maps. I'd definitely play this again a few more times.