It is hard to say exactly what is going on scientifically, but I have gone both routes and my advice is don't waste your time on short cycles. I don't know if it the fact that the body 'resets' some of its stasis points when it 'gets used to' being larger for a longer period of time, but any short cycle I did there was still some recovery time and the body found its way back to where I started from eventually. I also think that those of us that have a hard time getting large (true ectomorphs) will find it hard to maintain higher than natural amounts of muscle without gear in the long run. Once you hit your peak naturally, trying to maintain more is like a struggle with your body that wants to maintain less. I think alot of the people that maintain there gains without gear might have been able to achieve those gains without gear in the first place, maybe just not as rapidly.
These are my 'real world' thoughts on the subject anyway, not gospel.