I dunno how hard Miller hits, but he is very durable and fast for someone so fat. I think he mills most of the division in the 80's simply because he's durable enough to tank through everything. Early 90's wise however I think is when Miller runs into problems as this was generally the point where the powerhouses appeared. I could see several of these guys standing a chance at stopping Miller in a pure firefight like Stewart, Rudduck, Tyson, etc., but the risk is there for them too as he outweighs all of them by 100+ lbs.
A guy who was stopped by Dubois aint going to cause too many nightmares for fighters from the 80's and 90's. He is fat and useless
Nah he was never that good, his best wins are an old Duhaupas and Washington, not exactly the resume of anyone who was a serious contender or even a genuine top 10 fighter. 80's era was ravaged by heavyweights strung out on coke but even that era had enough quality fighters to ensure Miller never achieves much. Dubois is limited as hell, makes Bruno look like Larry Holmes in comparison yet he beat Miller, I really don't think Miller amounts to much in any era you put him in.
The 80s and 90s were tougher heavyweight eras then this one, I can't see him doing any better. I actually don't think he is totally useless though, if he could keep the weight "down" to under 290 I think he could be effective as a durable high volume guy.
Are you aware of how far and out of shape guys like Tony Tubbs - a guy who lived up to his name in spades - were?