Originally Posted by ccage
Ok, I haven't driven the car on the track -- not even autocross -- so take this with a whole shaker of salt:
The Porterfields feel to me like the have a much differently shaped performance "envelope" than the stock pads. Specifically, they feel to me to make higher friction over all, but generally at higher temperatures. It seems to take more pedal pressure to get the same result in braking, but if you keep pushing it feels like you get more overall friction.
At first it bothered me. I thought maybe I hadn't got them bedded in right, even though I followed their guidelines (and their guidelines made sense to me and others). Looking at the rotors showed a good bed-in. Then once I discovered the difference, it's actually kinda nice in that -- because the overall performance envelope is wider -- the lockup threshold area is wider, too, meaning that it's easier to find the threshold and hold it.
OTOH, you have to remember that when you get in it to go to the store first thing Saturday morning after not having driven it for a few days (or worse yet having driven your almost-identical-but-with-stock-pads-Miata all week), you need to allot for the fact that a) you have to push harder on the pedal and b) the brakes aren't gonna work as well 'till they heat up just a little -- which can lead to an oh $%$ moment. Ask me how I know. :)
Hope this helps.
Chuck