Well, bolt is 6'5 with long legs and Owens barely made 5'11 with rather average sized legs, so it is probably a bit more clean cut than you are giving credit for, but athletics lacks comparable restrictions like weight classes, so it's not exactly a relative comparison.
It seems that slipthejab won't give us a reply (we are not worthy!!). I think that there is a good chance that this is what he was talking about though https://books.google.gr/books?id=Mo...age&q=mike silver on pernell whitaker&f=false It's from Arc of Boxing, a book I remember him mentioning in the past. Silver makes a case why boxers of today can't compare with the old timers. Incidentally, in the same excerpt you can also find a few critiques about Mayweather too.