Myron,
I had Axxis pads, now run Porterfield.
The difference is so great, you wouldn't believe it.
For me, the stock brakes are great even on track, but are marginal in terms of overheating.
I never have a problem on the Nürburgring, but when I had to stop on track because of engine trouble, the heat soak caused the pedal to go to the floor.
Better fluid might help, but I suspect on a more brake intensive track, I may exceed the heat capacity of the brakes and woul need cooling ducts.