Something to consider is that a failure on a linerlock (not a disengagement, but a true failure involving damage to the knife) will usually jam the knife open, saving your fingers. This is not true of many other locks. While I was at Spyderco recently, I was able to examine a number of linerlocks that had gone through their "breaking machine." All that I saw had an identical pattern of damage, preventing the blade from closing. Furthermore, some rather unreasonable loads were put on the knives in order to cause this.
As far as the wear issue goes, my AFCK is over four years old and has only had much competition for "pocket time" in the last year. It locks up only a hair from where it did when new and passes a spine-whack every time. My other linerlocks (Military, Starmate, Wegner) all pass spine whacks consistently as well, and I expect them to wear even better due to their steel liners. I've never disengaged any of them accidentally. Finally, all four knives have a smoother, lighter, more even action than any lockback, Axis-lock, or Rolling-lock that I have handled.
Get my fingers in the path of the blade? When I cut myself closing a liner-lock, I'll let you know. Incidentally, note that a mid-lock lockback puts your fingers in the blade's path when closing due to how it is generally held to depress the locking bar. I now know to hold it close enough to the pivot to catch the "kick" at the base of the blade when it drops, but I have cut myself on these in the past.
I guess what I'm saying is that when a liner-lock is done well, I'll still take it over any other lock that I know of.
-Drew
