Initial testing on the PSS indicates that they should be a noticeable step up in performance. I'm more skeptical on the mileage claims. If someone is driving them the way the ask to be driven, 30K miles is a lot. Staggered fit will be warrantied 30K front 15K rear.
I have accepted a new position at Tire Rack and am no longer in the sales department. firstname.lastname@example.org
is available to assist with M3 questions.