Can usually get somewhere from 7-10 DA presses off before it falls off. I'd venture to say the slight vibration from the hammer striking the firing pin is what leads to it falling off more than any deviation with my trigger control, though I may be wrong. I can keep the sights in pretty perfect alignment all while I dry fire.
I don't want to blame it on the sights, though I do think they are a bit out of where they should be. However, analyzing how I anticipate they're off means my shots should be missing to the right instead of left.
I believe the issue may be in the upper body portion of my stance, but I'm not certain.