I have the Brembo setup and just wanted to chime in. I think the stopping power has improved, especially at higher speeds. The Brembos brakes make you feel more in control of the car. Also, going 100 mph and slaming on the brakes feels like you are stopping from 50 mph with stock setup. I dont know if its necessarily worth it for street use but if you drive your m5/m6 hard i think that what goes fast needs to stop fast.