I am on my second set of the Supercar tires. My years of autoxing street tires, including Mxx3s tells me that these SC tire hold their own with any street tire. I have put these tires to the limit on a banked sweeper at 135+ mph and around cones in first gear at 15 mph and they seem to be glued to the road. I never drove on Goodrich KDs, but a friend of mine did on a coupe and he said he thinks these SCs on his new Z06 are every bit as good. I got 11,000 miles on my first set and would have gotten another 2000 to 3000 more, but I blistered one running too many consecutive laps on a high speed track. I probably had close to 500 track miles on these tires.