I'll probably get them anyway... as the discs on the car now have seen better days.
As for performance of the standard discs.. I am not too dissappointed, I run castrol SRF and pagid carbon metallic pads and was outbraking virtually everything on the track last weekend..... not better than the best, but nobody passed me under braking.
However, if I used left foot braking all the way around the long long long corner going out onto the straight, I had the pedal going really low at the end of the straight.
Nothing beats bigger brakes.... but as I'll need new discs sooner or later I'll give these a whirl and see how it goes.

Conk.