I can only speak from my personal experience, but all the "natural bodybuilders" i run across only got fatter when they tell me that they are "225lbs" now.
They don't even look better, just fatter, if they would go down to contest shape they would be somewhere around 70-75kg, no matter if they started at 100kg with the diet or 85.
Another factor is that the natural guy dieting down from 100kg will NEVER get in shape, because he will lose so much muscle during the diet that he will end up skinnier than the 85kg guy, although he might hold 5kg more muscle before dieting.
I think it is bullshit that steroids build permanent muscle. Not even natural training builds permanent muscle, if you slack with your training or diet the muscle will be gone, albeit the natural muscle will be much harder to get back again.
BUT, all ex-juicers that i have ever met in my life that kept training had a far better body than people who had never touched steroids in their lives (but maybe they were on low dose test, i don't know).