I, for one, bought the game, but did not like it at all after I got to playing it. Like one before said, it has no depth. The single player, IMO, has a weak story, and there's not much beyond a couple of different mechs with a couple of different weapons. Ya, ya, I know, there's like 15 or something different mechs, but all in all, they are based on 2 or 3 different models.
The multiplayer is sooooooo boring. I've played a few games, and never heard any cries of stealing kills, but it's too plain for me. You aim, fire, and strafe side to side. That's it. You repeat that the whole game. There is no kind of strategy to the whole thing, unless you count strafing around buildings to be strategy, but then the building will only topple after a couple of shots.
If Microsoft can provide some new game modes via Content Download with XBL, the game will be much much better to me. Until then, it collects dust in my game collection.
All my opinion.