I have 7 EDCs in various blade and handle materials and of both lock mechanisms. By default I prefer the integral bar lock. It is a very strong lock, solid, and allows the knife to be as slim as possible for comfortable carry. Also, if you go to the EDC section of Darrel's revamped site, all the knives pictured there are mine
My 4" CF EDC, as 92degrees pointed out, is a liner lock. The handle on this knife is pretty thick - thick stainless liners, thick CF scales, it's built like a tank. The steel liners thickness is more than most liner locks, and as a result, the lockup is extremely solid with no play. On all 4" EDCs Darrel uses a full length solid steel handle spacer that also pulls double duty as the blade stop. What you have is a solid knife overall. However, the titanium IBL EDC's make great, well, EDCs
Relatively light weight and slim. They are quite stylish and due to the anodized frame they usually are eye catching knives, even for non-knife folks. I have recently been toting around the 3" EDC. Imagine the Camillus version on steroids. It is the same length but the overall thickness is considerably more. It is compact but powerful in the cut.
D2M is a great steel for this knife - holds an edge well, has lots of bite, and is relatively easy maintenance. I love the grinds that Darrel is putting on them now. He hollow grinds using 14" contact wheel on his slack belt to make the edge thin, but not too thin where durability is an issue. The result? My two 4" EDCs cut like friggin' lasers. And with the 14" hollow grind, resharpening them is quite easy and I can get a hair popping sharp edge every time. I have some older EDCs that are flat ground, and I can tell a slight difference in performace...but they still cut great.
Talonite is great if you can get it. Its non corrosive and non-staining. Basically use it, wipe it off, and go. It's a low maintenance blade material. From what I have heard from other sources, its a great material for field dressing too. The only downside Talonite has IMO is the high cost. But it is well worth it as a user though.
I love the EDC, its my all time favorite custom folder. Looks great, is a comfortable, well thought out design, and most of all a very well made folder. Whichever variation you choose you cannot go wrong.