The slot has a neglegable effect on pad wear characteristics... the slope of the slots and the incompressability of the brake pad material doesn't squeeze any decent amount of pad into the slot to be "cut off" as some would have you think. It's a myth.
Some people say slotted rotors dust more than regular rotors, but I could not find anyone who ran the same pads with both types of rotors and quantified the statement... thus, I will present to you that different pads dust different amounts regardless of what rotor is used.
The advantage of slots over drilled rotors is that the slots allow somewhere for gas build-up to go, but the slots also do not go through the entire disk. This allows the biggest advantage of drilled rotors without their major weakness: cracking.
There are NO cast drilled rotors available for the MkIII Supra. All rotors that are drilled were, at the time of manufacture, blank rotors (i.e. regular rotors). The blanks were then drilled with the hole pattern (hopefully in a manner that keeps all the veins in one peice. Consequently, if you buy drilled rotors, it's entirely possible to get a bum job.
Powerslot plated rotors are prime because they do NOT rust and possess the same characteristics or better of any other rotor available for the MkIII. Since rusty rotors don't shed heat very well, plated is the only way to go, IMHO.
As for this crap about the MkIII brakes sucking, they suck by reputation because people put cheap components on, don't bed in the brakes, don't change the fluid often enough, leaky master cylinder, or all of the above. Simply bedding in the brakes can net 20% more stopping power... probably the same amount one would gain putting on a BBK. And guess what! It's FREE.
Unless you have 500hp and track race it, the stock brake component sizes are quite enough to get the job done. I cannot fade my stock sized brakes on the street, as that by the time I've gotten up to speed to start braking again the brakes have cooled enough to handle that stop... and the next... and the next... ect. I've tried... It's impossible to fade my pad/rotor combo, as that the rest of the system will break down from heat and fail before the pads fade. The fluid will boil and the seals will melt, and I'm sure that the pad backing plate would probably melt too, possibly followed by the pad welding itself to the rotor if I were to come to a complete stop with the brakes at that temperature. But they wouldn't fade!
Even if someone was going to track race the car, I would tell them to put on some good pads and rotors and get out there. Replace them with a BBK when they aren't enough anymore. Tires and suspension will get better lap times than enormous brakes.
