I am not sure, I've tried the Porsche Cup (feels great btw) at Spa, and they are quite crahsy, especially on Eau Rouge and Les Combes.
Unfortunately the ai is still a mess just like after the last update, Before the july update I was praising just how good the ai was but after that it's just not fun to race against the ai. I've been doing a lot of races on Imola against the ai with the GT3:s but they really struggle. They keep losing the tail in a lot of corners which didn't happen before the july update. There are constant yellow flags and I can easily get up through the field just by passing other cars that have spun off. I really hope this can be fixed soon. Before the july update RRRE had the best ai I had ever experienced but now it's just a mess.
Also tested the classes with the new Ai on Dubai. First:great track, really enjoy it and the look is just superb. To the Ai (i use adaptive AI), yes they are spinning out really often in that weird section in the first sector, rest of the track they are fine. GT1/GT2 are struggeling to get the power on the ground out of some corners, but so am i. They are fighting each other as always and sadly stick their nose in every hole i let them in corners you normaly shouldnt do that. But i think they are adapting faster to my pase as before, which is nice. To the physics uptade to the GT3 Cup: Its way more forgiving now, i can actually catch slides. Did the challenge on Knutstorp, before this track was pure hell with this car. Today i did about 15 laps with many mistakes but no spinning out or worse. Its now pure fun and still a challenge to be fast. Really great