I prefer the 360's controller for racing/driving simulation game too whenever steering is not in use...b'coz the "R2" button on the 360 allows pressure sensitivity on the throttle...allow more control on the vehicle. While on PS3, the right analog stick offers similar function BUT the "kick" of throttling the pedal of a car is not there for me on the PS3 unlike the 360

On the bright side for the PS3 controller, the "R2" button offers simple pressing feel like other's regular button which mean games like DMC, WE2008 and some rhythm game are easier to control/handle compare to the harder and more effort to trigger "R2" button on the 360...juz my personal experiences and opinion...