I had already powerlifted and worked out naturally for 7 years before I ever juiced. I was 178 @ 7% bodyfat. I am 5'6" tall (short)
My first cycle was 500 mg of Sustanon weekly and 1 AD-50 (on workout days). I did that cycle for about 4 months. I gained 15 lbs of muscle and my bodyfat stayed the same.
When I came off, I eventually lost about 8 lbs. So the math says that I made about 7lbs. of solid gains that I still have today. My bodyfat right now is around 12% and I am at 200lbs. clean.
I think if you start with a hard-earned solid base, it is possible to keep something from a decent cycle. This is why some lifetime naturals can't stand competing against guys who juiced years ago.
One other variabe to consider: When you juice, you have a "Natural" tendency to work out harder. I have never let myself forget what that work felt like, so I still work out hard (as if I were juicing) today.
When you watch the highly debatable Skip la Cours workout videos, you can see that sumbitch knows how to work out hard. Whether he is juicing or not aint my call. Sure, he looks juicy-juiced, but the point is (for all you non-juicers)-- do you have any idea what it feels like to work out completely "JACKED?"
Something to consider. NO, you won't recover as fast, no, you can't work out as hard or heavy, BUTTTTTT!!!!!! you may pickup on a few intensity tricks that will help your natural-for-life mentalities. Some of you natural guys just aint hittin it hard enuff mang! Didnt Ice Cube say somethin like "don't stop guy hit it!" Goin do it, goin do it, goin do it to it.