Uh... Infinity Ward, WTH with no online achievments?
Single-Player:
I loved it. Better than the multiplayer, but only by a small bit. The game is really hecka hard on Veteran, and quote Kirstin Holt: "[it] will probably make you cry." The voice acting is awesome, but you'll shrug that off in favor of the ultimately great soundtrack. Dramatic moments also cause an intentional slowdown. Those are not caused by performance issues, but to increase the dramatic feel of the game. Well done, Infinity Ward!
Multiplayer:
The multiplayer mode isn't worth all the work. Sure, you get a lot of goodies, but what's the point without any achievments? You should at least get an achievment for being brave enough to give up all your goodies at a way later point for "Prestige Mode". So, that's a very weak point of the game.
Good:
-Deep singleplayer
-Great voice acting
-Great soundtrack
-Good multiplayer
Bad:
-NO MULTIPLAYER ACHIEVMENTS
-....and nothing else