I may catch flak for this, but I do think that Floyd could counter punch his way to a competitive UD here. Pryor did leave alot of openings while he punched and its not inconceivable to think that Floyd could punch "in between" Pryor's combinations and catch him with a shot he doesn't see. But I could also see Pryor doing more damage to Mayweather than any fighter he has fought before him has. Either way I think its an interesting fight.
Pryor wins by clear UD or kayo. I can't see how Floyd wins with his Hopkinsesque punch output. Pryor wouldn't be stopped by Floyd's power.