With all due respect, I think the lock time business is a bit silly. Yes, the DA fall takes a zillionth of a second less. It's lost in the noise of all the tomfoolery going on with the nut behind the butt, though.
FWIW, I shoot rapid fire better DA than SA. Applying force to the trigger tends to bring the gun back onto target for me, allowing me to get into a rhythm that I can't find with an SA pull -- on an auto, of course. When it comes to all out, take-your-time accuracy, though, SA wins out. YMMV, as usual.