I tested this tune using the 2010 #24 Jeff Gordon car on both DS3 and using my Logitech g27. There are quite a bit of DS3 tunes that do not work well for a wheel. (Either being too loose to the point of spinning you out or being incredibly tight.) On a wheel this tune actually works to the point of improvement. I'm sure there are other tunes that would much better for a wheel, but this wasn't designed for a wheel in the first place. This tune ended up being on the tight side.
First, I ran on my wheel with a stock tune and no aids. I ended up running a 1:09.401 after about 12 minutes of driving before applying the tune. I switched to the suggested Aids of TC and ABS at 1 and ran a 1:09.5xx on my first lap out. I ended up getting a 1:08.912 on DS3 with the aids after a couple of laps before removing them. With no aids after a few laps I ran a 1:08.512. I then changed over to the wheel and ended up running a 1:07.500. The only reason I was faster on the wheel was because I lack experience on the DS3 and as such I was able to drive more smoothly through the longer turns on the wheel.
This tune is obviously great for TTs as I was smoking the tires a lot once I switched over the wheel.
The tightness isn't as noticeable on DS3, but the lack of turning for the controller counterbalances that, but you can take advantage of being really hard on the throttle and it sticks just fine. At certain points it seemed that it was more natural to the optimal line on the DS3. It seems that the low spring rate and perhaps the dampers cause the tightness, it doesn't go over the hill well, but the transmission helps with that. The transmission is geared very nicely. Even with a bad run through the hill, I found the car rocketing away from my earlier (stock) attempts on the straight. It does grip great for the majority of the track.
tl;dr
Suspension: Causes understeer due to springs.
Transmission: Geared nicely.
