I don't own S&B/USO/etc but I've used all of them on borrowed rifles. I don't think USO's optical quality is any better than the other big names - after all, once you're using ultra-high-end coated lenses, there won't be much difference from brand to brand. What I like about USO is the custom nature. You can specify the exact tube diameter, objective size, windage and elevation knobs, illumination, reticle, etc. that you want, and they will build it for you. Plus USOs could practically be used to chop down a tree and still hold zero. That said, Premier Reticles has recently released a line of scopes that looks very interesting (they used to build the S&Bs for the military). I haven't gotten to use one yet but they look like serious contenders.
