Pros:

-Custom survivor dialogue at the start
-Good difficulty, just right
-Really cool locations, with decent variety
-Feels like a L4D2 map, rather than like a port of a L4D map.
-Fits into the official game's canon, in-between events
-Creative finale, very original.

Cons:

-No survivor dialogue anywhere else.
-HDR is all over the place. Lighting in general is VERY poor because of it.
-It's not clear what the generators at the finale do, or why we're starting them. Directions to the opened path would have been nice.
-A lot of crescendos use the default "Rescue is coming, defend yourselves!" text even though no rescue ever comes.

Conclusion:

This is an excellent map. The scenery is beautiful and atmospheric, it's diverse and interesting and the locations and transitions look believable. It has its hard moments, but overall difficulty is just right, making events spot on. It's a nice extension to the original campaign, and fits within events believably.

I want to give this perfect 100, but I can't, not with the atrocious lighting. There's no reason why the game should go pitch black in broad daylight just because I'm under a highway overpass. It looks like HDR adjustments are too severe, making some dark locations FAR darker than they have any excuse to be. Almost the entirety of the first map looks like daytime, but plays like 2 AM on a moonless night.

Fix the lighting problems and this campaign will get a perfect score.