Pros:

Excellent graphic.
Chinese things.
I like the Chinese witch.
Cola to get bomb.
Soldiers shoot survivors.
Enough supplies.
Cool and challenging finale.

Cons:

After finishing pushing the vehicle at finale, the defense was a bit shorter than expected.
A strange error at finale as mentioned at comment below, but don't know why it has gone without doing anything.

Conclusion:

Definitely worth playing. Another word, this is one of the BEST campaigns available out there!

I had to stop at many places just to look around and enjoy the scene. Same to witch, I like that Chinese clothes.

This is really fun playing from start to end, no boring part as graphic and scene are not repetitive. The hidden soldiers shoot at us was a fun too, challenge your friends if they can take it down without losing hp or with short time frame. Head shot it!

Pros:

Silent Hill style.
Excellent skin/model.
Hard and challenging.
LOTS of secret rooms.
Hidden items.
Way too many pill/adrenalin, aid kid, defi, grenade... (maybe this is cons, it made the campaign quite easy at map 2 3 4 5).
Dark and blur, hard for observer to explore maps.
Puzzles.
Unique.
No hint.
Feel like in Alien movie.
Made by Leafo.

Cons:

Lacks of great music/sound.
Lacks of Tank, should have at least one for each map. We only got only one Tank for the first 5 maps.
Not enough atmosphere.
Repetitive.

Conclusion:

AWESOME F*CKING AWESOME campaign, among the best available to date !!!

WARNING: This campaign is a path finding one, do NOT play if you have no patience. There is NO HINT, you must explore it yourself. That is the value of the campaign.

Map 1 is really hard because it is obscure at first, and start with nothing but pistol, it also took us much time the most. But the other maps is quite easy, because there are soooo many things to grab, and straight forward. Especially map 5, not sure why he made this one that short. 

Finale is great, works fine and got lots of secret rooms and ways there, but it is also lack of supplies compare to the others, so it is hard. When we reached this one, we were all in yellow or red health-bar.

In conclusion, this is really hassle and challenging campaign, but still much easier than Silent Hill. It took us ~3 hours to reach to the finale (played on Realism Hard). We found no bug yet. MUST PLAY if you really love L4D2.

To Leafo: This one is fully complete I think, so please come back to Silent Hill: Otherside of Life, I really love your mapping style, please finish it asap, and make more wonderful campaigns. Thank you very much for taking the time to create those.

Pros:

Excellent idea
Hard to complete
Great graphic
Make us thinking of what to build first

Cons:

What?

Conclusion:

An awesome, excellent, unique, replayable map.

Pros:

Lots of challenge
Traps
Creative ideas

Cons:

Not too hard

Conclusion:

Awesome, it took us all night to finish, and want to play it again.