I have been racing at Watkins Glen, not auto-x, so I'll share my thoughts on the S-03's. They are EXTREMELY responsive tires in the dry. Steering feel isn't all that great, but they handle much better than my old SP9K's. The threshold is a fun point to go to in these...in the D-Lops, the tires would screech like hell. In the S-03's, you get no screeching...just the start of some body roll and the hint of your ass coming around to give you the idea. I have yet to screech these tires, I'm not sure it's even possible. I love their street performance and wet performance, in addition to what I have stated. They are far, FAR better than the D-lops in every single area except steering. I will buy them again in a heartbeat.