Hi, Just wanted to add my experience. I ran 3 track days on my stock 18" rims with PS2's and I liked the tires on the street but found them to understear more than expected on the track and as noted above get greasy when hot.
Put the Vred Sessantas on about 3 months ago and they are great on the street. Stiffer sidewall is noticable as you hit small bumps or creases in the road but not bad at all. Then went to a track day at carolina motorsports park on Saturday. The things are much better than the PS2s. Much less understeer and handle the temperature well even when driven quite hard. No chunking and wearing well. Highly recommend.