DBA rotors, now running a lesser grade rotor and the rotor is perfect. They have done over 100 laps of Lakeside many hill climbs and some road driving.
Spoke to GSL and they give the REMSA a thumbs up, long rap sheet of exotic euro fits, vs HPX less squeal more dust.
Incompatible compound gas or chemical film (?) means machining rotors before changeover from HPX they say.