I use to race in the mountains of So. Cali. years ago. I never used a rear brake accept lightly in corners if I entered to hot. I had Harley's for awhile, and they tended to need using the rear a little because brakes were spongy at best. The height of the foot brake on the R3T seems a little high to my taste and I almost have to lift my foot to engage it, which affects my ability to feather it in an emergency. I only use the rear mainly two up and/or while pulling a camper. I can tell very strongly that it takes more effort to get the rear to lock with the car tire vs the ME880 I had on it before. I also have 15 k on this Run Flat running 40 psi and the wear is minimal.
As far as scientific data goes, nobody will touch testing car tires on bikes simply because tire manufactures will not support it. I know what I know because I had my first R3T Highside when the rear locked up when I thought I was just easing on it. Can I prove it is better? No, but I do have piece of mind.