Finally got BOs multiplayer to work yesterday. Gotta say the maps are good - not sure which one I like most yet, but they make a refreshing change from MW2. Knifing and spawning need some fixes, and the RC car shouldn't be a 3 kill award. Also, there seems a lot of micro management involved with all the customisation options (not sure I can be arsed tbh!)
As I've only had a few hours on it so far, I've not unlocked that much - currently using a M16 w/suppressor, makarov, hardened, ghost, tac mask, semtex, nova gas, claymore. Pretty good load-out so far. I'm getting a 1.5 kdr on maps I barely know at all.
Username on xbox live is F1lthyDuke if anyone fancies a match or a spot of zombies.