For some reason, my posts were “invisible” and did not appear. I contacted the moderator and apparently that has been corrected!
Mine continue to reveal more information as system resolution has improved. Last year, I updated the USB board in an Audio Research DAC8 to be able to drive the Sonore ultraRendu endpoint. Previously, it required drivers so I had to use a USB to S/PDIF converter. The results now are better. Even upgrading the DC cord to a modestly priced Ghent Audio starquad cable improved dynamics.
As for reliability, my 17 year old U1s soldier on nicely. The only periodic weirdness is the left backplate will sometimes noticeably increase output. I find that I need to cycle rotating the controls on the back to drop it to normal.
After reading of other’s success with bypassing the HF control with fixed resistors, I purchased some following Dr. West’s guidelines. Maybe some day I’ll get that transplant done!