Ceramic pads last almost as well as semi-metallic brakes, last longer and extend the life of the brake discs. They were great right away. Quiet and efficient. I thought I was driving a sports car because I could stop so quickly and confidently when exiting the freeway. I've used semi-mets before, but they're quiet and don't have any metal-on-metal noise or brake pedal feel. Feels like a new car! ___________________ UPDATE: After only 1000 miles they started squeaking in the morning. This may be due to unusually low temperatures in the Northeast or high salinity on the roads. I'm not saying these pads are bad - there can be many reasons for the problem. However, due to the squeaking of the brakes and the presence of grooves on the rotors, there is reason to believe that these are not the best pads. The rotors are harder than ceramic so the grooves wouldn't have appeared if the pads were good unless the pads were brittle or a faulty compound cut into my high carbon center rotor (they hold up pretty well in the elements, especially salt, by the way).