I've gotten around to making a make-shift setup in the living room now, and can confirm feedback is a-ok.
I've just set some times on the reverse track with it (which aren't so heavily contested as the others), with the MX-5 and Integra, I think I came in third (1'19.5 and 1'24.0 or something). The high-scores seem to take a while to update though.
Anyway, I have all the settings on as much realism as possible, no ASM or TCS, and I'm enjoying it a lot. Realism in the handling and feedback seems to have been improved considerably. Especially the part where you can oversteer and spin-out is a nice addition ...
(it was much harder to do in GT4)
Edit: wow, the Evo IV is much improved. Now it is a fun car to drive, with great balance and oversteer. This was one thing they got wrong in the previous games imho, the setup of the 4wd seemed to be geared towards rally no matter if you were driving on gravel or asphalt. Great improvement! After a few laps I also seem to have gotten the no 1 time, but by the time that's updated probably not anymore.
Still, at least it seems I don't completely suck.
Edit: in the Evo IV on the more hotly contested normal direction I got 20th.