I DON'T use my EDC to open boxes - mostly because I'd prefer not to get all that adhesive on the blade. Plus, I find cutting cardboard dulls blades pretty quickly. Most of my box opening only involves slicing through plastic or fiber-reinforced packing tape.

I DO use a folding utility knife to open boxes. The ones I prefer have the ability to flip/change utility blades without a tool, though I do have to be a bit careful - on one occasion I accidentally slide the release lever while opening a box and had the blade flip out (literally, not emotionally).

I find the folding utility knives to be kind of heavy for EDC - especially compared to my mini Rittergrip EDC. This is likely because of the steel slabs on each side - compared to the plastic slabs on the Rittergrip.

I almost always have several types of blades nearby and prefer to use what works best ... up to an ax, lopper (long handle - cuts small branches), cordless reciprocating saw, and chainsaw. But I don't use any of these to open boxes :-/