I have to agree with the writer of the review...no melee sucks. I can't remember a single time I didn't try hitting the B to melee the guy that was right on top of me.
This game is a buy, if you like shooters in any way, buy this game. The Co-Op is by far the best of any game ever (Including gears.) You can play any mission with any weapons, also the missions can be played with random placement of the enemy. I have played it for hours on end with my buddies.
The single player is good, but the story isn't that great, it is very unrealistic. There are a lot of things that happen in the game that didn't even seem real, and kind of pulled me out of the experiance. The A.I. is extremely good, everything from: Flanking us, using confusion tactics, and proper use of nades. It really adds a lot to the game.
Also remember, people online are really good; it took me a few days to get to the point were I was getting kills.
Game is worth buying and keeping, I know I will be playing this one for years to come.