as brake effectiveness. I have the 13" StopTech cross drilled rotors and 4-piston calipers in the front. The kit is 10 years old now and I can't remember much of the smaller OEM brakes. I do can tell you that the pedal pressure was not reduced and the brake effectiveness was hardly improved. I wonder how having a 4-set, 6-piston fronts squeezing 14" rotors and 4-pot rears performs. I think the PB vacuum booster is rather small in the Z for the job it needs to do. Not sure how the OEM master cylinder fares pushing against that much more volume of fluid.
Are you using the MC stop to avoid firewall oil canning?