Good post....this needed to be mentioned.
Many times I have seen guys around here mentioning their bodies don't require the amounts they needed in the past. Sure, they probably do everything a little smarter with experience wrt diet/training but there is no such thing as receptor down regulation. Like you said...the opposite is more likely to occur.
yah, doing things smarter.thats why less is needed i think.
and they still dont have the same mass like when higher doses, but something somewhat similiar.
and youre too nice on the first timers who gain 30lbs in first cycle, never ever is half the gains muscle, few lbs will be muscle,the rest, well, cswiolsis