let me start by saying I have the revolution kit and had 205 callipers before going the wilwood route as I didn't like the necessary modification's to run the 205 brakes.
ive done a few track days with hard sessions. I do run ducting to help and the revolution kit appears to be adequate, have temp stickers on the calipers and it never got the caliper temps over 150'c. I run ferrodo ds3000 pads and the bite is awesome and zero fade as expected they get better towards the end of the run....
from my experiences:
unless our going to run the W6A caliper or the TC6 ie the big pad calipers, there is no advantage to running the 6 over 4 piston wilwoods as the pads are the same size and the 4 are already verging on two much piston area. (long pedal travel).
if you want the 6 piston cool factor go nuts but performance wise the gains are minimal and its possibly worse depending on piston diameter selection.
oh and as for the differential piston bores I have no noticeable pad taper....
imo revolution kit, good pads and fluid and ull be fine for 90% of competition. and the 10% you wont have enough brakes for you would need a large budget so the AP kit would be the ideal option.
