I think it's solid, but it does have a few annoyances. For starters, the panzer soldats are a bit ridiculous at times. They're manageable on their own, but when there are 3+ on higher rounds while everything else is going on, they're very cheap. Getting the lightning and wind staff pieces are a chore, as the zombies can always catch up to the tank, and the robots are only where they need to be for you to be able to get the specific parts some of the time. Filling the chests can be a pain, because it's hard to predict when a robot will come along. Most of these things are just peeves, the soldats are my one actual complaint; they're what get me and my girlfriend 9/10 times.
The good definitely outweighs the bad, and Mob is the only map I like more on Black Ops 2. I'll just give a compilation of awesome ideas they implemented on this map:
Shovel - Allows you to get extra resources and plays a role in getting the ice staff, possibly among other things
Generators - This is a good way to mix things up with the power; having to go for the switch every game was starting to get old, and Origins and Mob shook it up. You have to maintain all of them if you want the Pack a Punch up, and particular ones if you want to use the perk machines there, along with the mystery box, and:
Wonderfizz - Basically a mystery box for perk colas. It operates the same way in that most of the perks you can get from it aren't available otherwise, but one is.
Staffs - Perhaps my favorite new feature, these beasties ensure that everyone gets a wonder weapon, and they're quite potent, especially if you upgrade them.
Tank - Though I don't use it too often when I'm not getting the lightning staff parts, the tank is somewhat similar to the bus in Tranzit, but the gameplay isn't annoyingly dependent on it. The tank is a great shelter from soldats.
Giant robots - Although they're why the wind staff parts are an annoyance, they do add an awesome feel to the map, and they require that the player exercises caution when they're walking about. Fortunately, they kept their stepping spots static, so the player is at fault if they're crushed.
Challenges - Probably my second favorite aspect, challenges allow you to acquire helpful things after fulfilling a specific task. Getting a free PaP'd weapon for getting 115 headshots is pretty awesome.
The Maxis drone - He kills zombies, picks up drops, and even revives downed players. He's definitely worth building, along with the shield.
I'm sure there are more that I missed, but yeah, this is a very fun map when you get used to it.
