Roy would completely destroy Floyd Mayweather Jr., just ask Floyd himself. He's scared of anyone with a great or super left. He wants fighters with that right hand where he can shoulder roll.
Jones Jr is the better fighter and would win. He wouldn't destroy him however, but Jones is a brilliant fighter so it wouldn't be that close neither.
Jones Jr. would win at catch weight, had amazing speed, and more power.
I would edge towards RJJ.
In his prime he was a machine, I doubt Floyd would be able to stop him.
Roy would have killed mayweather in his prime. Roy had the power and the speed.
Sweet Science fans,
PREFACE,
The following is asked ONLY because De La Hoya fought Hopkins. Oscar had the balls to fight Hopkins at catchweight, 158.
PREFACE,
BOTH in their prime, Floyd versus Roy Jones at catchweight.
Q 1. In a 12 round bout who is left standing at a catchweight bout:
Floyd Maybeweather
VERSUS
Roy Jones, Jr
source: curiosity because Maybeweather has never faced guys in their prime.