Good info, very handy to have.
I usually buy EBC direct from them, their prices certainly have gone up over the years.

Rear discs (rotors) and Yellowstuff pads now fitted (a week after the fronts) and the car stops like a performance car should. Very happy.

Based on my findings I would recommend checking your pads (wheel off and gently lever pads laterally in the caliper). One jammed in the caliper on the front and one on the rear. Same pads from new (38,000) and GM performance specialist serviced every year. The problem is you get used to the deteriorating braking performance (or at least I did) until it becomes obvious that it ain't stopping properly.