Completely agree with Jeff. This game is all at one level there is no sense of importance at any time because it's all "11".
Treyarch's waves to create difficulty is ridiculous. MW2 was challenging but never seemed to be based on just sending waves of enemy unending until you moved forward.
I had way more fun playing MW2 and more fun playing MOH. I felt more drawn into the MOH story because of pseudo-realism as opposed to Black-Ops, which telegraphed the "twist" making me feel a step ahead of the story.
As for MP, a patch/dlc to MW2 would have sufficed.... No genuine co-op or even spec-ops, just this zombie crap.... no thanks... I pre-ordered Hardened, completed on Veteran, played some MP and returned it... Very average, not inline with what I like about the COD franchise....