Up to 500 miles now on my XTMs. Very good re dry and wet traction, as well as quiet rolling, plus good on corners, etc. And of course they look great on the truck. The only negative vs KO3s is that the higher sidewall stiffness shows up as a bit more transmission of road surface imperfections thru the steering wheel. It kinda seems like tires out of balance, happening more noticeably at 60 to 70, but varies greatly depending on the road surface. Worse surface = lower speed for steering wheel movement. Gonna keep driving then until 1k and then try a bit lower pressure. Currently using the oem 39# cold. I may also make sure the XTMs are structurally sound by going to a local race car shop that's worked on my gt500, and have them do a road force balance. Their machine seems pretty darn good at correct tire/wheel setup.