Well, we, meaning Euclid, Reigninblood and I, did some comparisons last night while both their cars were stopped. I went in watch mode and observed both cars tire representations at controller (DS3 and DFGT) lock and while stopped the tire AoA appeared identical for both. I don't know if that's what you call it for cars, but that's a term in aircraft circles to describe the aircraft's Angle of Attack to its target. At any rate, we have empirical evidence that, at speed, and the higher the speed the more pronounced the affect is, DS3 users have increasing limited steering angle. Euclid and Reignin both reported, with their DS3s on full right lock, they could not get through the last 2 turns at Indy without lifting. After we finally beat Euclid enough to convince him to use his DFGT, he got it hooked up and he found out he only had to use about 20 degrees of wheel movment to get through both. I know from my experience with my G27, I was easily able to steer my car to a higher and lower line mid turn, in both corners, and still be flat out. I'm just saying, there are maybe 2 places at Indy that should require even getting close to steering lock with either controller, and really only 1 other track that has a tighter turn. At low speed the DS3 folks are getting close enough to full travel with their sticks they don't notice the difference. It was plainly evident last night, this isn't the case at higher speeds.
Don't get me wrong, if you are a DS3 user, and you have to lift to get through either of those turns and I'm behind you when you do, I won't be behind you for long.