Having had about ten USO scopes with four currently in possession this is my perspective. A few years back, when there were fewer competitors in the precision tactical market, a USO scope was highly sought after. However with the entrance of Vortex, Kahles and others the consumer has many more options. IMO options were USO greatest asset and Achilles heal.
As a result of the job shop layout, one of the great features of USO is the ability to Build to Order. There were many options of reticle, tube dia, knob configuration, etc to allow you to order the scope as you wanted. That was unique in the scope world. But the job shop configuration was also the big Achilles heal that resulted in uneven quality from scope to scope and countless combinations.
When USO transitioned from the SN-3 to the LR17 & ER25 designation they reduced the options down to the most popular configurations, which was a move to standardization and improved quality. Around the same time the Vortex Gen2 hit the market which offered the same feature sets, consistent quality, excellent warranty and fast (in stock) delivery) at a very competitive price. Vortex did their market homework and dominated the upper end of the market. Now USO was caught between the proverbial "rock and a hard place" of limited options/stagnant product development against a tide of competitors. USO has always had an excellent warranty but due to the build to order process, repairs/replacements could be lengthy.
The B-series were anticipated to bring USO back to the forefront but instead brought them to parity in a limited market full of choices.
I anticipate the next generation of precision tactical scopes will have electro-optic technology integration.