Taking my time w/ the new B3, still using the stock tubes, at least for a few more weeks. The one thing I did notice is that it did not pair well/ synergize with my SOTM USB regen. The soundstage shrunk and I was localizing speakers. I removed the SOTM out of the chain and went direct to my Innuos Zenith mk3 w/ FTA Callisto USB in line. Going direct opened up the soundstage again and allowed for the speakers to disappear as they had in the past in the room. Meh, not all gear has synergy, moved the SOTM to the 2nd floor smaller near-field listening room.
No complaints thus far, I am withholding forming any detailed opinions until the tubes and unit have had at least 100hrs of play time, just so that everything settles in. The unit is running balanced XLR direct into my Vinnie Rossi L2iSE feeding various speakers as my mood changes.
As it stands unless something drastic changes I can see myself enjoying this piece for years to come.