I apologize in advance, but this is a bit of a TL;DR. I know some will find it interesting/helpful so that is why I am posting this.
After putting a handful of hours into Mob of the Dead with supercoolisaac and a friend of ours, I can say that I enjoy the map overall.
Here are some things we enjoyed/found out:
*The characters add a whole new level of badassery to the Zombies gang (no pun intended).
*The Blunderbuss (especially with Acid Gat and PaP'd) and Tommy gun are awesome additions to Zombies.
*Hellhounds are located in 3 spots (near Electric Cherry, near the bench at the Docks, and in the room before the door that requires power to access the rooftop). In order to unlock the Tomahawk, you must feed X amount of Zombies to each Hellhound. Tomahawk spawns in the room in front of the laundry room after feeding the Hellhounds.
*Electric Cherry isn't really necessary, but it has saved me a handful of times and I prefer to use it over Deadshot.
*For those confused about Power, there is no switch. Afterlife is the key to unlocking nearly everything within this level! Each player gets 1 Afterlife usage per round.
*New PaP and Mystery Box skins!
*The layout of the level (although confined in many spots) is enjoyable.
*I don't recommend more than 3 players in a game as there really are only 3 good training spots (Cafeteria, Rooftop, circuit around the Docks --> Juggernaut Alley --> Generator Room). I suppose the PaP bridge would be an okay spot if you're playing with 4, but the map gets really cramped even with 3.
*We managed to figure out pretty much everything about the map including the first part of the EE. The only thing we don't know how to do is the second part of the EE, breaking the'cycle'. If anyone knows how to break the cycle, feel free to post here. We feel like it has something to do with the Blunderbluss + Acid Gat, but we aren't 100% sure.
RIP Sacred_Asylum 4/1/13 Watching you play SnD is like watching Mozart paint a picture. It's absolutely beautiful. -supercoolisaac