This thread should be sticked, hello?
Anyway, today I bought GSC because I was curious. I have to admit I don't like most of Niels mods for rFactor. Vette felt like brick on ice, Supra was just weird, not sporty at all and Caterham (which I believe Niels made tyres for) had "oh dear, jelly suspension!" feeling because of soft tyre compound (at least that is my guess).
Back to Game Stock Car - had some problems with installing it on Windows 8 RP (anti-malware-something.exe had to be killed via task manager, otherwise setup could not even start), then serial activation issue with "server-something-failure" but it runs fine now. Initially I didn't like the game, force feedback with DFGT was so loose at the center that I had no fun driving it. Also after playing iRacing (Caddy mostly) cars felt like understeering bricks with no life in them at all. However after setting MaxForceAtSteeringRack to -1600.000000 in RealFeelPlugin.ini under [StockCar V8] tag I finally felt what car is doing. FFB around center became much more firm and nicely smooth. Quickly changing front ARB to detached made the Stock Cars really responsive and oversteering which I like a lot. There is more grip than in iRacing and it's easier to save from spin. I would describe it as something between LFS and iRacing which is nice because I like both
. AI is nicely tweaked too, at least on Interlagos (which is, basically, the only track that I know in GSC
Bottom line - buy GSC people because it's good.
Other settings : degrees of rotation 720, steering lock 20 to 22.