Pros:

+That movie !!
+Large and several floors
+Many different ways to do it
+as good as campaign as survival
+a large amount of weapon
+ Day/night maps
+not so ugly
+detailed
+poster

Cons:

-sound desync
-A huge spot / bug ( search how to have gold medal palace on youtube ) 

Conclusion:

To my mind, it 's one of the best map for l4d2 . Excellent in so many ways excepted 2 bugs which will not prevent you to really enjoy the map.