Pros:

- incredible  survival experience
-awesome level based in the movie!
-gameplay style building the barricades
- scavenge  furniture in order to hold and survive
- lots of detail and cool design, well placed items 
- l4d traditional campaigns never going to be the same after this one!! haha

Cons:

- cant wait for more

Conclusion:

challenging level design, awesome innovation, that single map for me  was like  a whole campaign, if thats the 60% of the  whole proyect its going to be epic when it comes out !!! BIG THANKS  to Lou Saffire for the great work