Unfortunately I have not heard any speakers in the Usher line. Also seems to be harder and harder to find a place to audition speakers these days. Good luck in your search, hopefully another member will soon chime in with more helpful info.
Give me a call if you want to chat about them. I know a little more than a little bit about them. I designed the crossover that was used in the BE-718's that were distributed in North America, and I also designed an upgraded crossover for the BE-20's that was not used in the production units.