this is getting better and better. i compared 0.17 to a project cars 2 night replay video, i don't see much difference tbh, in some cases this one even looks better.
performance issues i mostly have in replays with those cams which have a large view of all cars, which are far away, shading dynamic headlights. i think the performance in this case would benefit if the farest cars don't shade any headlight or a downgraded-headlight quality, not sure if that's possible.
heavy track for performance is f.e. highlands, but like mentioned above, it's mostly those far-away cams which hit the fps down to 40fps sometimes.