I'd still find it cowardly. How badass is someone on PED's? Not as badass as a lesser fighter not on PED's.
Marquez hired the best dope expert in sports before the Pac fight, his so-called strength trainer is also the best expert at cheating drug tests. He told on his friends to keep from doing time in prison.
It's quasi-legal in pro bodybuilding and the man on the street still calls pro bodybuilders cheaters. It wouldn't be any different in boxing. Casual fans would constantly complain how the new PED fighters are cheaters and how it was much better in the old days.
If he does, everybody's going to say he juiced so the win would be "tainted". Not a smart move from Tony