I'm moving my mk5 over to a 300prc for 1k plus yards and putting whatever I decide to get on my 6.5, which I'll take out to around 1k yards and in. Mainly used as an all purpose type of rifle. Honestly just looking for the best option in that tier of scopes that isn't overly heavy, has good glass, and is reliable/repeatable. The arken ep5 looks very promising, but I keep coming back to the ts20x due to the weight and lower magnification(2.5-20), just haven't found many guys that're running them. I'll check out the forum you suggested though, appreciate it.
Honestly, I know nothing of the newer USO scopes. I know they were great back in the day...But I do know that a buddy was ordering one of the "budget" USO scopes, I want to say it was the TS20X, but after he shot a few rounds and glassed-around through my Arken SH4 Gen2 6-24x50, he cancelled his USO backorder and ordered and Arken. Like I said, I don't know what he saw between the 2, as I haven't looked through the USO, but he obviously didn't see enough difference to pay all that extra money and wait for the USO, either...
For the $1,000 and under category, the Arkens hit pretty hard. Honestly, just comparing inside the house, the EP5 has WAY better glass than my Strike Eagle 5-25x56. IMO, the Strike Eagle is more on-par with the Sh4 Gen2, in all categories. But that is just my opinion... Take it for what you will. The ONE thing I like about the Strike Eagle over the EP5 is the locking turrets, and the fact that I can remove the turrets and reset them to zero, with a simple plastic tool, and no tiny little set-screws, and it's SUPER easy to reset the turrets, and to install the RevStop zero-stop setup. I also like the fact that the RevStop goes backwards 0.5 MILs, incase you need to take a closer shot than 100 yards. It's just a nice little feature. But, glass-wise, the $799 MSRP Strike Eagle is right on par with the $449 Arken SH4 Gen2...Through my eyes. Everyone's eyes are different. Both scopes track well, both have great turrets, both have 34mm tubes, both have a good bit of adjustment (the Arken has a good bit more than the Strike Eagle, especially after zero'ing your rifle, and setting the zero-stops). Both have lifetime no-BS warrantees, both have good customer service, but the Arken actually comes with a precision tracking guarantee, and the Vortex does not.
Like I said, both have their pros and cons, it's just a matter of what you are looking for. I will say this, while I have not looked through the EP5 outside, comparing it inside and side-by-side with some of my other scopes, the glass on the EP5 seems REALLY clear and bright. I have high-hopes for it. And honestly, for the money, I think it's going to be REALLY hard to beat.