After two sets of new rotors it's finally time for me to get rid of those pads. I know how to lap brake pads properly, but they started pulsing on both sets of discs within a few days of installing them. Without going into too much detail on how brake pads work, it appears that these pads transfer material unevenly to the rotors and the symptoms only get worse as they get hotter. A quick google search tells me I'm not alone.