I've had now and have had scopes from many of their generations. It's a sad tale of inconsistent quality seemingly precipitated by changing leadership.
My SN3's in 3.8-22x are frickin good scopes. Fantastic clarity, perfect clicks, dead nuts tough.
My TPAL series 10x37mm ST-10's were the same with slightly better optical quality to my eye than my SN3's. Extremely expensive for a fixed 10x though.
My B-17 was quite good in some ways but not quite up to the older standards in others. The turret lock was a particular annoyance, seemed like a poorly engineered afterthought. The click values were dead nuts though. That said, I do know someone who imported the B-series to his country for a while and he was finding the B-series to be no bueno in the click consistency department.
I'd put their older optics up against Nightforce, S&B, Vortex Razors, Khales etc... any day of the week for click values (and yes, I've owned most of those too) and in many cases for optical quality. The new B-series, I'd stick those alongside Burris XTR II. As well, the new tool-less turret is in fact not entirely tool-less and came loose on me multiple times in matches. The windage turret now has pinch screws on the cap which also came loose on me at a match and during a class causing no shortage of havoc. I hate pinch screws on turret caps. So, Iit feels like they cheapened their optics a bit with the B-series a bit but didn't reduce the price accordingly. It's still a pretty good optic but 3k? Naw.
What was actually bad? Only my ER-25's. I got them around the time USO changed ownership recently and it looks like they pumped out a ton of iffy ER-25's which I got a couple of. Return after return didn't get them fixed but did cost me hundreds in shipping and so I eventually got rid of those and brought in Vortex Razor 2's to replace them which gave me too many turret related problems and were heavy as hell. So, in the end, I found some older USO's with the ERGO parallax (because I prefer objective bell parallax adjustment) and those now live on in the collection.
I'm a USO fan but that doesn't stop admitting the fact that they've been hit and miss for a while now.