I was thinking about this even more last night and I have another angle on it. I was thinking, for myself, I would become way too obsessed with something like pumping in an extremely unhealthy way. I think that I would way over do it and rely heavily on the temporary gains it gave. When the swelling went down I think I would start seeing my "normal" girth as pathetic compared to my pumped and it would cause a vicious cycle of compulsion.
I see some of the pumping groups out there and the size these guys pump to is ridiculous, unusable and scary. I don't want to psychoanalyze these guys but I think in someone like me, someone with extreme o.c.d., I would take it to an unhealthy level.
The Girth I have gained with traditional Penis Enlargement is real, permanent girth that will not go away in a couple hours. This may take longer to aquire but anything worth having is worth working for.