I like them. On some heavier-duty straps it can be a pain in the arse getting a tool in to grab the bar, big potential for damage to the strap and scratches on the lug and as you said, QR bars negate both of those.
I have considered before the possibility of it getting snagged, but on what? I don't think there's enough purchase between my skin and the little knob to pull it back sufficiently to release, or at least only a very tiny chance.