Floyd will get utterly wiped out today. Look at the size of Julian, Tony, and Muguia. These guys are all 5'10-6'2 and walk around at 180 pounds of pure muscles. Floyd walks around at 150-155. Floyd's era was filled with pretty small fighters that he could walk down(Pacquiao/Marquez/Mosley/De La Hoya/Hatton)
For comparisons
Ricky Hatton is about half the size of Muguia. Yet if Hatton was fighting today? He and Muguia would have gotten matched up. Now Floyd is more talented than all these fools but size wise he just couldn't take the punches. Realistically all the 147-154 guys today would have been MW-SMW in Floyd's era.
I think if Floyd fought in this era, he would be fighting at 140 and below. Which means he won't have won the belts at 147-154 the way he did.