With the GP calipers, the billet design makes them lighter, as well as stiffer. The design does bring with it better pad retraction especially when the pistons have special coating such as tini coating added.
For race purposes, the easy pad removal makes them well worth it. I know I can swap out pads in less then a minute (both sides).
The Mono Block brings to the table the fact that the entire unit is one solid billet block (not two halves bolted together).
The stock units found on the Duc and Aprilia are about as special as the Nissan. Simple cast just like any other caliper you would find. The main difference is the Brembo logo
And possible a little better pad retention/removal setup. _________________
Charles Gallant