I hate playing SF4 on PC simply because the vast majority of people have really, really BAD computers. I can play like 3 laggy people in a row on PC, then go play SSF4 on Xbox360 and nobody lags at all.
I honestly feel that the SF4 match-making lobby should continually FPS test your computer and report that # with your ping. IE: I'm locked at 60 FPS / 23 ping, that's a good match up. Would make it easier to weed out the garbage.
I really hope SSF4 AE comes to PC. Because when the competition is fierce, the lag low, and the computers decent it is the best way to play an SF game outside of the arcade.