Just about everyone is gonna say Leonard because people that are fans of the old school fighters will always pick on resume's rather then fighting styles.

Leonard never really had to deal with anyone with Mayweather's speed, defense or style and Floyd hasn't fought anyone like Leonard.

But the thing is Mayweather's style could give someone like Leonard trouble.

But people look at old school fighters as fighting the rougher tougher fighters of their generation so they will place them classes above.

I wouldn't be surprised if Mayweather won honestly, but it would be a close decision because there will be some rounds where Mayweather outboxes him, and other rounds where Leonard outhustles him.