You hit the nail.
Alcon, AP, Brembo, Project Mu, StopTech, K-sport,D2, and all other HUGE caliper/rotor combos are mostly radial mounted, and for bling bling cars..
Yeah, they look nice, but a wilwood caliper at 4lb's will function well, and not add a bunch of unsprung weight. Not to mention the huge price with big brake kits.