I thought that the answer to this question for me be to simple to even require a question before I started thinking about it. I have a Driving Force (not pro) that I got at the same time as when I got GT4, when it came out. Ever since I have been driving with the wheel because I thought it was faster and it was just more fun. Sure, when I raced my friends a few times I would let them use the wheel because it's fun, and I would use the DS2. But then I started thinking, am I really faster with the DF than I am with the DS2? I decided to do a test to find out, that test was the 24 hour Nurb test with a BMW GTR Race. I started out with the wheel, and was getting times like 7'10, 7'05, 7'02. But I could have been a lot faster if I hadn't of kept going off the track, and to make things worse, the FF made it nearly impossible to recover when I had a wobble. I switched to the DS2 for a few laps, and amazingly, my times were around 6'30, consistently, and I went off the track way less often! I was greatly surprised by this, and because of it I now use my DS2 more often than my DF.