I like a 4" folder for my EDC and that's just too much weight at the bottom of my pocket. With a clip, it sits just at the edge of the pocket where I can draw it without rooting around. Using the clip also keeps the knife vertical, which makes is less bulky feeling against my leg. If I'm wearing thinner dress pants, I'll choose a smaller, lighter folder like a Moki or Al Mar, but still use a clip. Frankly, I don't know how I got along for so many years without one!
My next project will be a pocket sheath for the folders, to try to get away from the exposed clip, but I don't know if I'll be able to deal with all that mass in my pocket on a regular basis.
Stitchawl