I have a paid of black diamond drilled and grooved discs in standard front G40 side - 239mm.
They have done 15 laps of Oulton park and have been freshly skimmed - had a wobble under braking which I thought was warped discs but it turned out to be a loose hub nut in the end.
These were £120 new.
£60ono posted.
Pics to follow.