On OEM brakes I'll eat through a set of front track pads (PF01s) in 2 weekends.
I have never been to the M School but been to the PDC. From looking at the schedule and seeing it in action, I consider the M School as the precursor to an HPDE. At the M School, it seems like you learn the basic techniques in an environment more conducive to quickly building the fundamentals needed at speed. Versus starting out doing HPDEs and kind of learning car control, spin control, and basic techniques at speed. So I think you need a lot more times to get it right in an HPDE environment. I think the Advanced school is more like a HPDE.
Unfortunately, a lot of people jump right into HPDEs like I did. I wish I would have done some, actually, a LOT of car control work before going to an HPDE.
2013 F30 328i Melbourne Red
2011 E90 M3 Monte Carlo Blue
2004 E46 M3 Imola Red