Performance seems up on 164 for me, stays well above 60fps unless racing with AI. My only complaint about the graphics are the ugly tree shadows that cast onto the track.
Only drove the F1, DTM and Caterham so far and they feel great, they just need to feel more lively under braking.
SMS are really churning out the tracks at quite a rate, T10 should take note. The new additions are nice but even though I'm familiar with these layouts they do feel quite different in pCARS to what im familiar with. Some straights feel shorter, some parts narrower and corners have less flow and they seem to undulate more than I've seen in many other games.
The game is making great progress overall.