So my friends and I have played about a good 10 hours so far just with multiplayer. My brother and I beat single player in maybe 2 hours? We ran through it so we could play the Nazi Zombie mode which is pretty cool but not something you could play back to back because it takes a while.
I will start with my multiplayer thoughts. I do not think it is better than Call of Duty 4 because it does not an M4 and it is not modern warfare. That does not mean the game is terrible at all, it is a lot of fun. Treyarch has done a lot to its multiplayer that I wish Infinity Ward would of done or added later on. Such as separate leaderboards, more maps, bigger maps, online stats and much more.
Spawn points are ridiculous too. We can only hope they get fixed. Grenades are not as powerful as they were in CoD4.
Single Player Campaign and Coop is just alright. Not much a story what so ever, CoD4 was much better campaign. Coop works but it is not great. It works just like multiplayer does and picks random levels to play on. Yes, you can vote each map as they are in order to play the levels from beginning (Semper Fi) to the last level (Downfall) but that is a big inconvenience. Most achievement do not count either for playing in coop and are single player online, so that is kind of lame.