I haven't juiced in 3 years. I was on everything (human grade, vet stuff, mixes, blends, and doses that make my liver hurt just thinking about) for 6 or 7 years prior to that with hard training and a good diet. I honestly feel and look better (and bigger) than I ever did "on-cycle". I do feel you can change your structure and lean body mass with AAS, and once you go off you can continue to grow off of what you've gained... Just look at some pros that aren't competing but continue to train as an example. I have recently trained with Jim Quinn and he's still as big as a house and in great shape without the gear...and yes he still has insane vascularity in his legs. (remember that old Twin Lab ad?)
I do believe that you can use AAS just like any other "supplement" to achieve a physique that is radically different than what you started with. I also believe that you can stop using AAS and continue to build off of your gains......when you do come off it's just a matter of being able to get over the fear of stopping. You know, taking off the superman cape, hoping your bench doesn't drop by 50lbs and that you won't be "small" etc...