IMO, it's more of a gimmick. Mine is a part of my "representative sample" collection.

I have an early Kershaw/Ken Onion model. It's gorgeous--rounded, polished G10 handles, titanium liners, 440V steel, scary sharp out of the box, & holds an edge well--so far, and has no lock. I've never had a problem with it opening in my pocket--though when dropped, yes.
It's become my Sunday/dress clothes knife, because of those rounded edges--it's not as hard on my clothes.

The assisted opening mechanism is nice, but not necessary for me. Most of the knives I carry are one-hand openers (can even do it w/a couple that aren't so designed), and most are also ambidextrous. The Kershaw/Onion has a non-reversible stud, set up for right-hand use only, though it can be used by the index finger of the left hand.

The torsion assist is fast, & impressive, but I can't easily open it in church to trim a string without a noticable "click" that can be more easily controlled in regular knives.

I like mine, but as I've said, it's relegated to a secondary use role. FWIW, I think the Kershaw Black Out and new Leek are the two best designs to date.

David