I didn't say it was his physical prime though. It was his absolute peak as a boxer. I have Hop's career set, he was a better physical specimen when he beat Glen Johnson in '97, but that does not mean he was at his peak as a fighter then. He was still developing his style then. His prime years were roughly 97-02 or 03 (he was already past-prime by the Oscar fight IMO), and the absolute peak best version was 2001.
Personally.... Mayweather Calzaghe/Marciano Its hard to split JC & Rocky in a p4p sense - not in a legendary sense as Rocky being a HWT gains LOADS of points - but there is not a huge deal between them IMO. Mayweather is a better talent than both of these guys IMHO, thats my opinion.