Advantages to a one handed folder? Many many - Picture - last week, I'm up on a ladder bundling cable - I tend to do it the "old fashioned" way, with lacing cord - take the spool of cord, cut off a 3 ft length, make your loop, grab you cables, tie, trim. Notice the steps "cut" and "trim" - Knife comes out, cuts the cord, gets folded, gets put back in holster, so it doesn't get dropped. Did that maybe 30 times that day.

Opening the mail - Mail is in left hand, reach down with right, grab knife off the belt, open knife, open envelopes, close knife, put it iway

Once you get use to them, they are just so much more convienient

As for Autos - not around here - not legally anyway. I have been tempted to by a Leek, but more because of the blade shape than the assisted opener - and now that it's coming out in s30v....