I love it! But its not perfect.
Its going to take forever to finish everything. On cod4 i was 10th prestige level 55 and finished almost all the challenges. I would like to do the same for this one, but its going to take forever. Especially since there are challenge for each attachment and they have upped the amount of kills you need to finish a challenge. That and the fact that the maps are bigger is awesome though I think because I don't think the game will ever get stale that way.
I have noticed that people like to camp, but I dont think its different than cod4, there are just more places to do that now. Once you learn all the spots you'll be able to take them out.
I think the overall look and feel of the game is a little more arcade like than cod4, but its not bad. I just hate the way the invite system works. I also need to get used to the new way of using claymores.
The game is fucking badass and I think it will only get better.