I put a caliper comparison up
on our blog. The Brembo Mono 6 is a great product. It has been used successfully in a million different brake kits, and has a lot of satisfied customers. That said, it was designed with different goals in mind vs. AP Racing's CP5060. Or, a better way to put it might be that the Mono 6 had additional design requirements that a racing caliper would not have (painted finish, to be used on a wider range of applications including trucks, winter road use, etc.).