It's definitely fun.
Just hit 2nd prestige on PC, must say zombies has been keeping me VERY busy though. I think I have like a 2.1 kdr or something.
Try this, get a friend with voip and enter a game like multi team or team deathmatch, can be search and destroy if you really want it to. move slowly throughout the map, actually check each corner and communicate what you see, sort of like a well put together squad in bf3 would do. Now throw in some random rules, we had ones such as no sprinting when you're not being chased/chasing, when checking corners and generally moving around you have to crouch, you can only use your crossbow from a distance OR you may try to sneak up with a combat knife. It's actually REALLY fun, especially when you creep the fuck out of people on the other team in the lobby w/ voice chat.
But yeah, we both had the same name & classes, black hat, c4, combat knife, crossbow, sometimes the crossbow is replaced with a silenced sniper or semi-auto pistol.