Sooo your saying that half inch length and .25 girth is possible and will be permanent without maintenance?
These are my opinions, based upon experience, and upon info that I trust...of which there is precious little:
Girth for certain, as I've personally experienced the girth growth. The length...maybe...I can't speak from experience on length growth, as I've only gained girth via pumping and will absolutely not attempt stretching. But a few members I trust here have had modest length gains via stretching and jelquing.
The gotcha with all of this is the time investment. I pump on occasion and only as a fun add-on for sex. But I've been doing this for nearly twenty years (I forget exactly when I first started), and am an easy gainer. The guys here who stretch and succeeded put in unreal hours...8 hours per day, 5 or more days per week. Sorry, but spending most of your waking hours clamped in a traction device is like a damned prison sentence, and the meager results are simply not worthwhile. Plus, there seems to be far more regression than I'd be happy with.
There's also the individuality factor. Everyone is different. Hard gainers, easy gainers, some gain and lose quickly, etc. There are no guarantees whatsoever. As I said, I pump for the fun of it...it feels good in the pump, my wife enjoys the variety of a thicker cock, and I have no expectations of permanent gains.