I did a little test, which probably says a lot or nothing at all, depending on your point of view. Personnally, I'm not trying to make a statement here, just wanted to find out, how good/bad the race_s-setup might be.
I took the XFG out on bl1 (a combo which I have not driven in a very long time. PB is 1:34.10 but that was in may 2006) and dled Duck's current wr-setup (a setup I'd never used before). I messed around for a few laps and then did 10 consecutive laps. My laptimes kept getting better with the very best being 1:34.40 on lap 7. All the laps afterwards were in the 1:34.xx range.
Then I took the race_s setup, messed around a little and did 15 consecutive laps. The very best was 1:35.79 on lap 9. From lap 5 to lap 15 I managed to get all sort of times from high 1:35s to high 1:37s -- consistency was non-existant.
So, whatever that means
.
Note: I never do my own setups, because I have no idea what to do, but I can get within 103% of the wr-time within around 20 laps in the easier cars, which could point to the conclusion that I'm okay at adjusting to setups.