Bob, didn't mean to slam PowerSlot...well, yes I did. I had them on my 98 F-150 and they were destroyed in under 30K miles of use. The machined surface of the rotor actually broke off and rusted. I had never seen a rotor fall apart the way the PowerSlots did in less then 2 years of use. Also, they never say any hard use or hard braking that would have caused these problems. I was shocked at how bad these rotors looked after normal use. I really believe they are manufactured from inferior grade metal, and thus don't last long. I really have had longer and better service from cheapo rotors I purchased at Advanced Auto Parts for 30 bucks apiece. As I side note I replaced the PowerSlots with EBC brake pads and rotors and they worked great, they were still on the truck when I traded it. I was impressed with the EBC stuff.