I think he was just expecting more out of an M. The Porsches won't melt like that stock, the M3 is the worst stock brakes on a car at that price/performance point IMO.
That said, I love my M3 minus the brakes and the PFC pads do help quite a bit. Stock pads are pretty pathetic though, they literally crumble. No such crumbling on my Cayman S or other Porsches I've driven. And if you want to say well that car was 800 pounds lighter, the stock GT-R brakes are better too and it is heavier.
And it's hard to understand the difference in how hard an advanced/instructor pushes it versus a real pro until you ride with one. Strauss drives indycars after all.