It has to be Floyd for sustained dominance. At his peak, I believe Roy was better but the end came abruptly. He was literally the Jordan of his sport. Roy's style was based on his athleticism and as you get older something has to give. For all of the talk regarding him not always fighting the best opposition he fought Toney when they arguably were the best pound for pound fighters in the sport in their prime of their careers. He outclassed Toney. This should not go unnoticed. I still give the edge to Floyd for longevity.