I just replaced my stock rotors and pads with ECS Geomet slotted rotors, and RacingBrake XT910 pads. The pads are supposed to be an in-between pad for aggressive street and very light HPDE use. I will most likely just use these on the street, though I will try them out on the track next month to see what level of heat they can handle. If they can't, I'll run a true track pad when at the track.
I've run ET800 RacingBrake pads (as well as ET500's) and found the 800s very good on the street, though I still managed to smear them once. I think I'm a pretty aggressive braker, so that's why I'm trying this new (to me) compound.
As you can see from the pics, the pads haven't yet fully mated to the rotors (you can see where the Geomet coating hasn't yet been worn off near the rotor center), so I haven't done any aggressive bedding yet. That said, the combo is quiet at can be, even in really cold weather. I do *always* use Permatex high-temp ceramic grease on the pad-to-caliper contact surfaces (don't go overboard with this!), so that tends to keep my braking systems quiet in most conditions and allows me to run more aggressive compounds on the street.
Initial bite is as good if not better than stock pads, and the pedal is *much* stiffer, which is awesome because I don't like a soft pad at all.
I did not bleed the fluid when I did this install, to keep the variables fixed.
Will post up more here as I get the pads bedded and can give a more informed review. In the meantime, I'm happy to answer any questions.