I didn't read all 7 pages of that link but the guy in the main part was misinformed on his need for rotors, by the numbers stated he was well within the service life of his rotors, keep in mind BMW intends the rotor steel or ceramic is suitable for pad replacement as long as it is above min spec at time of pad replacement, knowing that rotors may drop under spec during life of replacement pads has been considered by the engineers that developed the spec.
And the consumable mass is approximately 200 grams per rotor
How that guy went through 4 sets of pads in 4000 miles is shocking, I've got a GTS customer with 20 plus thousand miles and several track days and still on first set of pads
