I downloaded the demo last night and gave it a try. Fortunately, I didn't experience any of the "bugginess" that others have reported (I did experience some @$$holes that were killing their own teammates, though). The game is pretty cool, and I will probably pick up a copy when it becomes a little more affordable.
One thing that I didn't like was that you, by default at least, control planes, tanks, and jeeps with the keyboard and mouse. It was pretty hard flying a plane with a mouse. I'm going to try and configure vehicle control for use with a joystick, and player control for use with keyboard and mouse. If this works, then the game will be totally awesome.
E.