Oh... I should follow-up my own message and answer your other question.
If you put the 6's on the front and stay stock on the rear, I've heard this is a nice balance and you don't need to play with pad compounds at all (and it's a cheaper option.)
On the track I've never experienced fade, but ymmv. What I have experienced is heat. These suckers are hot! It's mandatory IMO to put really good brake fluid in the car with these, and a Dali brake deflector or something similar will help a lot as well.