On my Z06 I currently have the BFG KDW2's in the rear. These tires are AMAZING! Two days after I installed them I autocrossed the car, and had a blast. I was pushing the stock F1 tires on the front as the rear just melted and hooked 95% of the time. These are by far the best tires I have had on a RWD application.
With the stock tires I could blow the tires off in 1st and 2nd gear, NOW all I get is alittle chirp from 1st to 2nd. These tires have also made the mtns a huge playground.......I would recommend these tires to anyone looking to push their car to the limit!
I have also heard similar feedback about the new Kumho MX's as well. For now I will stick with my BFG and will soon replace the front F1's with the KDW2's