I have these on my car. The stopping power is definately an improvement over the stock ones. I do a lot of highway driving with a lot of fast stops and I notice a hugh difference. The only thing I have noticed is when the whether is cold and wet you just have to brake a little earlier to allow the pads/rotors to heat up. But that is only after you have been driving for along period of time without using the brakes, but my stock ones did pretty much the same thing.
