So today April 14th 2017 I installed a full set of Power Stop Z26's on my Grand Prix GXP and after about 30 miles I'm still not impressed. They don't really differ from regular premium brakes. There is a lot of squeaking, scraping and friction. I'll drive a few more miles and see if the noise goes away and then do an update. It is now April 26th 2017 and I must say that I am now very satisfied with the performance of this brake kit. After a few kilometers of driving, the brakes worked very well, all the squeaks and creaks stopped, and the car stopped again as if almost new. very impressive. Therefore, I am officially increasing my rating from three (3) to five (5) stars.