I agree 100% that it would likely be better injecting closer to the blood vessels in the muscle.
The article I saw on subq for test and stuff of that sort, said that it was better for keeping stable levels, but I don't think you get that blast that I like after a good IM injection, lol, but I may try the subq when I start to cruise in a few weeks just to see how it goes and get a couple blood tests before and after. I've never tried growth tho, I'm only 5'7" 145lbs, and I'm trying to get back to my 167lbs that I was before I had both my knees replaced 4 years ago, now that I'm able to do more grueling workouts.
I'll update here when I do the blood tests tho, maybe that'll shed a lil more light on the subject.
But either way, be safe man.