Havoc,
It is far too simple to just say that with steroids you either "keep your gains" or you "lose them."
It is all a very individual thing...for example, I am about to start a second cycle, a very light one consisting of anavar, creatine and large amounts of alpha lipoic acid. I fully expect to keep all the mass I gain off of this cycle, and even if I were to never cycle again, I would continue to make progress beyond my post cycle condition in all areas, maturity, density, size and shape.
Now there may be a point you would reach if you were to use high dosages over a long period of time that of course you certainly could not maintain naturally, but even then because you had used for so long you would have achieved PERMANENT increases in your so-called genetic limit...and I don't believe in such a thing either...
If I were you Havoc, I would not even think about AAS in your situation, simply because you can still say you are that size and natural which is very impressive...however, keep your mind open and remember that there are many here that have no clue about diet, training and their bodies and therefore cannot hang without drugs, which is their fault, not the drugs....
Remember, steroids simply increase the rate at which the body builds muscle...it is up to you whether you keep it or not.