Just in case anyone was still on the fence about this game, here's my opinion about the PC version: don't buy it, at least not yet.
When I came home with my new copy, first thing I did was play a single player map, and my initial impression was "hey, this is great! it must be incredible when you're playing with people!" The game ran at a very smooth 80 fps or so and I was quite happy. Jumping online tho, to play the exact same map I had just played in single player, was a very disappointing experience. My framerate had become incredibly choppy, and it was very difficult to aim. Looking around online, I found out the framerate for multiplayer games is LOCKED by default at 20 fps!! You can bump it up to 30 fps, but it's still quite choppy. I can't imagine why they'd do such a thing, it's very annoying. Rumors are saying that they'll eventually release a patch to unlock the framerate, and I advise any would-be buyers to wait til then.
If you say you just want this game for the single player, well, while single player is fun, this really is a multiplayer oriented game. You won't get $50 worth of single player fun =P. And with the way the game is now, I won't be getting $50 worth of multiplayer fun either.