Pros:

-awesome!
-perfect length
-every single random trap and obstacle (see below)
-perfect graphics
-great dialogue
-no bugs or problems whatsoever

Cons:

-None!

Conclusion:

Ahhh! Purgatory! Oh, wait. Nevermind. 
That map was so cool and so much fun. I'm a huge fan of puzzles and obstacles so this was a treat.  I don't wanna give away any of it, you guys gotta download this and play it to see.

Pros:

-Yay, updates!
-relocated L4D survivors
-new, realistic cave
-better finale
-long and entertaining
-no crashes/no bugs

Cons:

-none whatsoever!

Conclusion:

Like I said below, I can tell a lot of work went into this campaign so I appreciate it and really enjoyed playing it. I could just copy and paste what I said below, but I enjoy being complicated so I'll just type it out all over again. The first time you made this campaign, and the first time I played it, I thought it was long, redundant and the finale too difficult. The original cave was cramped and difficult to maneuver in. Now the campaign is fantastic, the cave is really cool in that its got a green hue and looks like convincingly realistic. I certainly wish I knew how to make a campaign like this. Outstanding work and thanks again!

Pros:

surprise tank in the mall :)
more creative mall scenes
you get to actually go into some of the stores
more game-play interaction
"Hank" dialogue
nice and open for proper navigation
well made, does not look fake
more climbing! I love climbing :P

Cons:

the first time I played, in the first level, my bot had no voice
I played on easy to see how different it really was-a bit too many tanks on the rooftop 
too bad there weren't more changed maps ;)

Conclusion:

I actually enjoyed "dc" better than the original L4D2 version. Cities and malls have always been a favorite of mine, though. I was listening to my own music so I can't really comment on hearing any of your background music, I'll assume it was great because DBD2 had cool music. And for that same reason the tank was a surprise to me. You're very creative. You should definitely make more campaigns, though, in my opinion.  Thanks!

Pros:

excellent graphics, FX (not for a moment did it look fake)
no noticeable bugs
long, challenging map
absorbing
dark, but not too dark
SI in just the right places
maze-like
dialogue
wall poem...very funny :>
The fact that you guys stuck with it and didn't give up

Cons:

slightly hard to navigate in places but, hey, the real world wouldn't have arrows and safe house signs everywhere either

Conclusion:

This is definitely a well thought out campaign with plenty of blood, sweat, and tears contributed. Big thanks to the I Hate Mountains team for putting tons of work into it (like two years) just for two hours of zombie action and player enjoyment.

Pros:

-super creative
-long
-absorbing
-an obstacle, not just run and shoot
-lots of elbow grease, nothing was overlooked

Cons:

I guess I'm having a brain fart!  ;)

Conclusion:

I absolutely loved this campaign. Its obvious a lot of work went into making it and I only hope I can be half as creative and talented in making a map as GARBAGE BOY. My only disappointment would be if it doesn't get recognized by Valve. Seriously. Great job.

Pros:

beautiful detail
excellent campaign
long
really defines "custom"
no shortage of anything, i.e. weapons, ammo, melee
I love the illusion floors near the end
FUN!

Cons:

NOTHING!

Conclusion:

This campaign was so well made, it deserves to be recognized as an official Valve campaign! The finale's a surprise, but its so much fun. Every level was something new and I never got bored. I definitely recommend people to download this campaign!

Pros:

Decent length and difficulty for only 3 maps
good lighting and sound
nice finale

Cons:

I almost got worried at the end of the finale, I thought the tank was gonna drive away and force me to go to the subway  :)

Conclusion:

I really enjoyed the campaign. It wasn't as long as the original Dead City II, which was fine with me. The difficulty make up for the length. And I definitely enjoyed this finale better than the original.