I have just tried that mod, all i can say is STUNNING!!!!
I never liked F1C before, but with that mod, it's really impressive. CTDP has done a great job, I hope the rFactor's mod will be as good as this one (maybe even better
).
I really like the feeling with the steering wheel(small bumps, braking, locking wheels,...), that's the thing i don't like in GP4...You can't feel anything in GP4
Anyway, I still prefer GP4, even with the bad feeling of my wheel, because the replays are just gorgeous to watch again and again, and (most important) the game is fluid all the time(in F1C, sometimes you don't know why, you get 10FPS for 2 sec, then 50FPS for a min. then back to 5FPS for 5 sec....)