I've used Hawk HP+ and now I'm using the Carbotech XP10 in front /XP8 in rear combination that so many SM guys use.
I've been happy with either, the HP+ work better as a dual purpose pad as the Carbotechs need some heat to really get the car to stop but once warm they slow the car down much better.
Can't go wrong with Porterfield either, I've heard other good things in addition to what James has said.
I'll give them a shot next. It'll probably be mid-next year before I need another set of pads, I just put the XP10s/8s on. Where do you go to get them?
And, how are they going to work with my rotors that have been used with the Carbotechs? Am I going to have to resurface?