I received this game yesterday and it is very good. Controls take some getting used to (probably because i'm used to COD4 controls) but once you have the hang of them the game gets even better.
The levels are very long and to complete them you have to use your tactics and the other members of your squad. Unlike most FPS's, you actually have to think about what you are doing in this game.
I have only briefly tried it online, there was no problem finding available games and online play was very smooth and fast paced.
5 out of 5!!!!