I thought ceramic were harder than semi-metallics? If that's the case then the ceramics would have warped the rotors quicker.
The "Ceramic" term used in brake pads aren't really the ceramic or porcelain / china term used in stuff like turbine blade or heavy duty parts. What we called "ceramic" in brake pads seems to be more of a mixture of copper and a bunch of other materials that are not as abrasive as the semi-metallic pads which chew throw the rotor to stop the car.
