I'd say get it. I loved the single player, I don't care that the story is stupid, it was fun, wild and action packed and that is all I ask for in a FPS.
The multiplayer is fun and don't listen to the pathetic whiny reasons people on here hate about it. It's a fast paced game where you require good knowledge of the map, good skill and a good mind to play well. Everything can be countered decently so there is little imbalance.
You don't get all the stuff at the start and have to unlock them as you level up so it's rather unfriendly to newbies and we all hate the noobtube, that's really the only bad things in it.