When I started out my priorities were
1. Reliability
2. Accuracy
3. Ergonomics
4. Trigger
5. Sights
Part of being dumb is you are eventually dumb enough to slowly acquire some wisdom hopefully. With enough problems and waffling I've come to prioritize availability above all as the best ability. A gun can be exceptional at all 5 of those things but it's meaningless if not on my person. This has become #1 for me now when considering a carry gun.
I am just curious what more experienced members of the forums value in terms of their EDC guns? No need to list them in rank as I have, I would just like to learn more. Thanks in advance!
I have found that concealability is primary for me, which is directly related to your concern of availability. By this, though, I don't mean the smallest gun I can find. Rather, it is about fit and ergonomics given what I usually wear and where I am likely to go (95%) as well as where I may end up (5%, which may be a place where getting made with a pistol would bring undesirable attention, negative PR, etc.).
Over the years I have figured out that a thin gun is more important to me than a small one, given my body type, daily activities, normal mode of dress, etc. For many years this was a 5" 1911, strong side IWB, and I ultimately settled on a spread-loop holster (Milt Sparks Watch Six, VMII, etc.) as being best. This concealed better than a Summer Special style holster with the loops on the holster body. I can hide that setup equally well under a suit or under an untucked t-shirt, with two spare magazines (Kramer double-magazine pouch) on the weak side behind at 8:00.
On days and for purposes where that was going to be too much to keep hidden, an airweight j-frame would be used, either IWB (again, Sparks VMII) or in a pocket or, worst case, on an ankle. For extreme cases, I'd use a Seecamp.
Over time, the allure of capacity and weight reduction reared its head, and a G19 came into play. Same holster make and model, same location of carry. It was definitely easier to make that I was carrying a gun with at platform than the 1911,
or at least it seemed like it to me. Just the slight difference in shape and thickness made a difference.
I was not as confident with this setup in certain modes of dress, or with my other double-stack setups (5904, 5906, CZ75), which left me catching myself doing the various "tells" of adjusting and checking during the day. A related aspect to this was weight balance - a double-stack magazine puts a lot of weight above the belt line, with relatively little barrel below the beltline to counteract it moving about. I can more easily and confidently conceal a 5" N-frame IWB than I can my 5906, for example, at least without cinching my belt down like crazy.
I later shifted back to thinner guns from the G19, which for a time were aluminum frame 1911s (Commander size and Commander slide/Officer's frame). Concealed just as well as the full-size, but weighed less, which was nice.
After a time, ended up adding a K9 Kahr to the mix with the hope that I could stop swapping 1911-to-J-frame and back, and just use one thing for all instances where pocket or ankle carry wasn't required. For the past three years, that has worked. This is with two spare magazines on the off-side.
I think there is a benefit to limiting the number of platforms carried. Muscle memory is the big thing, of course, but not having to buy multiple versions of expensive holsters (especially if you like leather ones) that take months to be made, and not having to remember multiple manuals of arms, that stuff matters, too.
Beyond concealability, reliability is a deal-breaker. Apart from a couple guns that had a tendency not to go 100% into battery 100% of the time, again, quality guns seem to not have notable reliability issues. I'm talking tens of thousands of rounds without failures to feed, extract, or eject. I know you can usually induce a failure by limp-wristing, but that's not what I'm talking about, though it is probably a good thing to test - how much limp-wristing will a pistol accept before it chokes.
In 2023, there is no reason for an autoloader to be finicky in the way we accepted autoloaders would be decades ago. It should feed, shoot, and eject all first-tier defensive loadings - Gold Dot, HST, Golden Saber, Ranger-T. If it doesn't, it is of no use as a defensive pistol
or carry ball if you must use it as a defensive pistol. In all cases, though, use quality magazines, keep your gun lubed to the level it prefers, and feed it quality ammunition.
Moving further beyond concealability and reliability, I'd say that ergonomics matter. Slides and hammers that bite, recoil impulses that bash the middle-finger knuckle into the trigger guard, controls that cannot be accessed without significantly shifting your grip, these are not acceptable because they are avoidable. There are enough good pistols out there that if you find yours doing this to you, try a different one. Same with grips that are too skinny or too wide for you, or triggers with reach that is too long or too short.
Rounding out the list, sights and accuracy are also important, but relatively less so. Each of us have eyes that work better or worse with different sighting systems, so try a few and pick a sighting system that works for you. As I get older and my eyes get older, systems that worked well for me at 22 years old when I started wearing a pistol on a daily basis don't necessarily fit the bill as well now. Sights are relatively cheap, so try a different type (especially on a gun like a Glock that is super easy to change sights on) and see what you prefer. Maybe you like a wider rear sight gap? Maybe you want a tritium front and black rear? Maybe you like bar-dot, or figure 8, or something like that? Try it and find out what catches your eye quickly while still allowing you the level of precision you require.
Mechanical accuracy of all modern, quality pistols should be sufficient for defensive or legitimate offensive use (e.g. actively seeking out threats that need to be eliminated, as LE might have occasion to do) at reasonable pistol distances. Accuracy deficiencies are attributable to operator error far more often than they are truly the fault of the pistol being mechanically inconsistent.
Beyond that, with a few decades of daily carry behind me, I'd just offer the suggestion to pick something that works and stick with it. Buy a duplicate (or two or three) of your carry piece(s) and your carry holster. Stock spare wear parts. Maybe just stock a full set of spare parts, period. Stock a good supply of range ammo and of carry ammo. Buy extra mags and mag parts. Dry fire a lot. Get to the range reasonably often.