I have the Assos S5 F13 and the Uno bibs. Love the chamois on both of them, the F13 has a thinner chamois, more panels and a "racer" cut. They feel like a second skin and are priced like it as well.

The Uno ones have a more relaxed fit and a thicker chamois. My butt says they are still superior to the 4D PI chamois.

Is there a Rapha dealer in Phoenix? I'd like to take a look and buy a pair of their bibs to compare if they seem to be comparable to the Assos ones.