which scope is better or are they for different roles thinking about getting 1 of these and getting rid of my ta01 nsn what is the reticle like on the us optics

I've got very little experience with US Optics. However, this is what I believe. The ACOG will be smaller and lighter without giving up anything on durability. I believe the US Optics unit will be powered by batteries, the ACOG is not. Just a couple brief comments. I'd like to hear someone who has used both somethat regularly chime in myself!

I've seen 2 types of reticles on the SN-4. One is the circle/dot and I have owned the DOE Mk 2 scope. On the DOE, the whole reticle lights up, unlike the NSN on the center part only. I think the battery life is 9 hours on the highest setting.

USO blows trijicon away in brightness and clarity. My biggest complaint about the trijicon is that i can't see the reticle unless i wear glasses. All USO scopes have the adjustable diopter.

smaller lighter and more robuster....
and that is ideal....in a packing rifle optic imo

I've just bought the USO SN-4 - literally just bought as the scope has not even arrived as yet.
(Surprisingly, I found that DOE stood for the Department of Energy.)  Also I have a couple of TA-11's so I'm about to find out if all the things I've read and heard about the quality of USO optics are true !!

Trijicon has been the choice of several military's besides the US special ops, and those are a serious recomendations, plus thru my personel experience says I must concur with.
Good shootin, Jack