Hi there
Well I took the M3 to Curborough knowing there was not much life left in the Alcon disc and pads but I thought small circuit so no issue. Even in this state the stopping power is still unbelievable but saying that it is the only car that feels as powerful on stopping as my 911 did on ceramics, only difference being the M3 is very dusty but the low disc life could explain the increase in dust on front wheels in last few months:
Really impressed with how long these disc have lasted, goes to show Alcon are fantastic quality, no idea on price yet but I only need to buy outers from Alcon so should not be too severe.
But they have worn beautifully and even and have done a huge amount of track days, remember I purchased this brake kit as used from a CSL owner who'd done a few track days and road miles on them too. Very impressed!