I have many knives. None of these issues are deal killers, just preferences.
And who are you calling old? I'm just middle aged. Well, on the far end of middle aged, but I guess I'm still cranky.
I am old, and act even older as I grew up with mostly grown friends. I thought my classmates were silly, even in college. I also have a fairly nasty form of arthritis, and "tension tremors" in my hands, so I'm picky about knives in that I want ones I can "draw" and open/close easily with one hand. So far, the PM-2 fills the bill.
Back to the thread, I've loved every Spyderco knife I've bought. That said, I only buy the ones with a prominent "Spydie-hole".
I've become something of a super-steel snob, and we can discuss for days which steels qualify for that title, and that's because I'm damned tired of sharpening knives. I once enjoyed it when I had a lot of slack time at work, but my "hand" in sharpening on a whetstone or diamond sharpener now varies so much in angle that I went to a Tri-Angle sharpener. There are better sharpeners, I imagine, but I'm a boarder and have no good place to put one.
I like finger choils, they don't snag on things if you fill the choil with your finger. I was the cook in our home until I started working such ridiculous hours that my wife took over - but that was 15-20 years after we married. When using a chef's knife I preferred a large one and I almost always "choked up" on the knife as much as possible with my forefinger on top of the blade, so choils work great for me. What's worse is that I learned to cook with what's commonly called a Chinese cleaver (it isn't, it's a proper vegetable knife), and I could seed a bell pepper or do even finer kitchen work with one.
Due to hand problems I can't reliably used a thumb stud, but flippers and compression locks are great - but I much prefer the latter.
Liner locks don't feel secure to me. Most are brass, and I've worked enough with sheet metal to know that brass has a mind of its own, work-hardens easily, and is prone to small parts made from it snapping without warning.
I should close by saying that I'm just a knife
user (thanks/no thanks Amazon), and not a collector or enthusiast.