I was at Streets of Willow about a month ago. It was about 100 degrees and the track was very hot. The sessions were about 20 minutes long, I believe around 12-14 laps.
I was in S5 MDM most of the day and the DCT was flawless. It really shines on the track. I ran S6 DSC OFF for one lap and didn't have any issues. The S6 shift though on the straight is neck snapping.