That's surprising to hear from a PC gamer like you. Some of the best driving games ever are on the PC. PC is versatile enough to basically work with any genre. Saying that racing games suck on the PC is almost as lame as saying that the PC only has RTS and FPS games.
Going back to the original issue, I also bought PS3 versions of multiplatform games several months after launch to boost my PS3 collection. I came to my senses though when most of them had noticeably worse graphics,framerates, and crappy tacked-on six-axis controls. Bottom line, when in doubt, get the 360 version.
