They are manufactured to be abit better then OEM spec.
Do not compare this to $1000 per pair Project Mu SCR .
We used RDA rotors for the rear on our EGK20A and our laptime spoke for it self ( 1:09 @ old wakefield )
Paul from ISMR used it aswell on his EG.
Mark Pakula is using them aswell
We sold alot of them already in the past couple years.