Hi Derek,
do you actually get brake fade on yours ?? As in same braking point same, entry speed and you end up with a somewhat mushy feel in the pedal and a longer travel until you end up with enough braking force ??
The reason I am asking is because I have run my Xfire very heavily through my local canyons and have not noticed a decrease in brake performance.
But of course I don't run multiple laps through the same corner either, so it may have just "felt" ok.
If I have a few quiet minutes at my local airport I'll try to make a few consecutive braking passes and measure stopping distances.
One other thing you may want to research before that IMHO is the brake balance of the XFire....I think there is too much front bias dialed in from the factory in order to avoid the onset of the tail getting squirrly during cornering/braking. Maybe one of the Xfire techs knows of a way to adjust the bias....if possible on the fly.
Speaking of airports...that aileron thing....now that sounds interesting, but remember that that will introduce adverse yaw which you'll have to compensate for somehow ;-)
Depending on the price of admission for the Brembo set-up I might be interested just because of past experience with them.