I have not used the USO 1-8x I have heard good thinks about it.
I have used the Vortex 1-6x, Swarovski 1-6x, Leupold 1-6x, and the Leupold 1.1-8x. I really like them all.
• Vortex 1-6x really nice glass, very bright RED DOT, rock solid construction, 30mm tube, great price, and SFP holdover reticle. (Heavy scope)
• Leupold Mk6 1-6x really nice glass, very bright RED DOT, rock solid construction, 34mm, exposed locking turrets (love these turrets), power rings very easy to use without a through lever, light weight, and an FFP reticle that work at low power without illumination. Little pricey but with it.
• Swarovski 1-6x amazing glass, very bright RED DOT (illumination system rocks), rock solid construction, 30mm tube, very light weight, and SFP holdover reticle. Very pricey but is a Swarovski.
You pay for what you get. Hope this helps.
Mike @ CST