Well 99% of the time I wouldn't really need the rear kit... in fact I can put more aggressive pads on and be fine... maybe 0.1s slower otherwise lol
Well unsprung weight does matter - so lighter brakes will make your suspension more responsive. But the trade off is the more mass the more heat capacity the brakes will have. Having 6 pistons in the trophies help because it spreads out the heat - pad surface is much bigger. Also the milled out areas in the caliper actually increase surface area which will also help a bit. Also anodized aluminum is actually an excellent heat conductor versus bare aluminum. I'm not sure how paint conducts heat but it's hard to get better than aluminum with type 3 annodizing.
Yeah I can bleed the brakes without removing the wheel