I like it. Clean and straight forward.
Only thing I'm seeing that I'd look into changing is the categories. Namely "Tactical". To me it's the only one that doesn't give you a good idea what's in there and then when you look at it it's got everything from apparel, knives, gear, and some things listed elsewhere.
I'd move some things to categories they'd already fit under, like your tactical optics could either be done away with or listed under the optics category. Then I'd get rid of tactical and rename it Gear or Apparel or something like that and list the appropriate things there, and then I'd give knives/knife accessories their own category since hte bar looks big enough to fit another one in there.
It also seems like several sub-categories are duplicated in multiple lists. For example, knives are listed under both shooting and tactical. Loaders under both Shooting and Magazines. It seems like it could be cleaned up and consolidated, which makes things easier to find (or see outright that you have in the first place), as well as making some of the lists easier on the eye by not being so large.