I've got the Porterfield R4S pads. They require extra effort to stop when cold but once warmed up but then they really work well, so I can't recommend them for every day. They also make some noise for the first few stops when cold. At the track they work great. I have a year on them and the wear is minimal. After the last track day I had some material transfer to the rotors. There was an accident and I didn't cool them down properly. The rotors haven't warped and while I have some slight grooving on the front rotors, I don't think it's excessive. Overall I'm happy with them for how I use my brakes.

Les