Yes same as Manny and a few others. Floyd is 3-0 at 154 and all 3 of his opponents won MW belts. That really says it all. At this time there were many more big fights to be made at WW then at MW. There was no reason to go up further than 154. All the pressure was on Floyd to fight Manny. If Floyd had went up it would have been to grab a belt to say he did it and came back down. Now whether he could have had a title reign at MW without losing is another question. While hes probably capable the risk of losing would have been greater.
Against the opponents of the last 15 - 20 yrs? At his best Yes. It's more of an indictment of the competition or lack of than his greatness .