I tend to do a variation on Mentzer's theme all the while keeping in mind that he built the majority, if not all, his muscular size and strength while on drugs. Some days I do the same number of sets I do on HD days, but instead do sets of 20 and more with much lighter weight.
Without a doubt, drugs make training far more productive and thereby easier. I have witnessed such transformations and it is nothing short of amazing. Of course when you stop, it goes away faster. I have zero doubt that if I were to take as much or even half what Mike used (minus the meth) and trained like Mike, I would get bigger and stronger with every workout for more than a few workouts. I still think training a maximum of 4 times a week is much better than twice a day, days 6 days a week but on drugs gains are going to happen with either system.
Since the early 60s, drugs have been the factor between winning and losing in bodybuilding. Mentzer was no natural mesomorph. Few are. I do think it has gone far beyond a reasonable approach and needs to stop being rewarded but the fetishists out there may not be large but they are in charge.