The main thing that puts me off AC is the lack of car groups. Even when cars can be loosely matched by era there is too much variation in performance between them. You would be lucky to find 2 or 3 cars from the same era that have equal performance and even then that would be track dependent. Eg Group C, classic DTM/touring, classic F1, classic GT/sports. I mean what are we supposed to race against the 935?
Another thing is that for me many of the cars just feel outright strange Eg Porsche 908, Alfa GTA, M3 in fact now I think of it, most of them!
I can't understand the lack of support for Raceroom
OK it might not have the depth and some of the features of AC or even PnG (setups) but it's a great package and most importantly....never fails to produce excellent racing.
My racing is more limited these days but I'll try to support whatever the sim.