Pros:

-Pretty thorough re-skins of survivors, infected, and melee weapons. First person arms look very nice and most of the Special Infected were well-picked. 
-Clever use of crafting tables for puzzles.
-Nicely detailed maps.
-Love the Enderportal~
-Herobrine!
-Well-placed dialog snippets. ("Does this look like home to you, Francis?" "Go to hell.")
-Good length.
-The dead youtubers were a nice touch, had fun looking around to find them all.
-Not too tough, but not too easy. Just the right amount of hordes (but maybe a few too many Specials; they're still manageable though).

Cons:

-No gun re-skins.
-The witch-chicken makes no sense, but it was funny.
-The Nether replaced Commons with Zombie Pigmen...when they were being used for Chargers already. I realized after that Chargers were bigger.
-The Nether map itself was pretty confusing, could have used a little better design. We got lost in that map a lot. 
-The snow got downright blinding in places, making navigation difficult.
-The End could have been more interesting and explorable, and the pitch black sky disappointed me a little.

Conclusion:

A wonderful Minecraft map! It was a blast to play, and I recommend it to anyone who enjoys Minecraft. The majority of problems are minutia that are easily overlooked. It was a great treat for my roommate, who's a huge Minecraft fan, and even has some good replay value if you don't find all the youtubers in the first go-round.