I have to say that I'm a bit surprised by the comments that AO is useful. I actually like AO, but in my limited experience the difference in speed of deployment can only be measured (if at all) in fractions of a second and I'm not sure how that could make any practical difference other than in a SD context.
For example, while I can deploy a Leek faster than a mini-Grip, I suspect that if I timed it, the difference would be measured only in 10ths if not 100ths of a second. I also have one knife that by design requires two separate movements to open, so the difference is much greater there, but I can still open it in a second or less. So the question that comes to my mind is, in what circumstance other than SD would it be of any advantage or utility to be able to open a knife in .1 seconds as opposed to 1 second?