I spoke to Sid some time ago about the "non-Detonics" pistol he was carrying. He was apparently having back problems and his doctor told him he should carry a lighter weight gun, (which is what he was doing). Likely that would explain the carrying of the pistols with alloy or plastic frames.
I have back problems too, but I find that if I switch to cross draw carry from time to time, and wear suspenders so that my shoulders carry some of the weight that otherwise used to tug my spine to one side or the other, I have minimized the back problems. I've even created a "special" pair of suspenders just for this purpose and they work great. (Hmmmm... maybe there's a marketing opportunity here??)
...Deeton