I've EDC'd a number of knives over the last 30 years, from the Gerber LST to a Strider SNG. They all have their pros and cons. What I've found for general use is a number of features that fit into an overall work knife.
Blade steel: super alloys are nice, and keep an edge for a long time, then take hours to get it back. On an EDC knive, a edge that cuts doesn't necessarily mean thin and hard - some prying and levering is included, a high alloy blade can chip or even crack. Any good carbon steel will do, L6 or A2, in stainless, from the chinese 18chr13Mov, AUS6, AUS8, 440C, ATS34, up to S30V, which isn't cheap. The midrange alloys do a good job, with a medium stone have a toothy edge that gets through double corrugated cardboard, a tough challenge.
The blade can have a thumbhole, stud, or disc to open it, but every one of them delivers a bit different leverage for that size knife in YOUR hand. You simply have to try it out to see if it works for you. Blade grinds are more specific to separate tasks, a leaf or drop point is better for general works. Full flat ground from edge to top is harder to make but cuts more smoothly. Most quality kitchen knives do that, and the lower the swedge, the more of a prybar it is. And cheap.
Bladelocks are a matter of much discussion. Any of them can fail, which is why some recommend no lock at all - you never get dependant on it, and use the knife safely. Or, learn better. Well, lock or not, you will still get cut. It's part and parcel of using any tool. The primary concern is largely liner locks - they have to be made correctly, and the more reliable ones share common features: The leaf material is a least half the blade thickness or more, the leaf length that pivots is as long as possible, and the material is not the same. What you get is a lot of surface area at the lock, in a disimilar material that has more friction, at the least angle to walk it out of engagement.
Handles come in all shapes, the simpler ones work better as a tool. Width in a carry knife across the back should be less than 1/2 inch, and pocket clips make them extremely easy to access. They are molded or fabricated from nearly everything. The best overall seems to be G10 fiberglass - it's not the most expensive, it's extremely tough, warm to the touch, grippy, non electrically conductive, doesn't deform if tightly held in a pocket, and low key. FRN is used on some good knives, but to do it right needs full liners. Aluminum is consistently too slippery in use and not durable.
Two knives seem to have most of those qualities for a good price, the Spyderco Tenacious, and the Benchmade Vex. More alike than they look, they have full flat grinds, a hole opener, G10 scales, liner lock, pocket clip, and have been on the market long enough we know they perform. There are more expensive knives, but for value - dollars per "usefulness," they are simply more expensive than they are 100% sharper or easier to use. What you get are brag rights about shape or exotic material - not being a better functioning tool.
Knives are largely more cosmetic than men want to admit, they don't just carry them for cutting, or a cheap slip out box cutter with a hardware store logo would be the normal thing seen. I prefer knives that are competently built tools made to cut, not the latest tacticool SEAL endorsed $350 collector a real soldier would leave at home - if he could afford it. It's a work tool for cutting, and they have developed into some really great tools once we learned better and left the Buck folder where it belongs - in the '60s.