I am now getting some time on my new Vivaldi stack (sans transport) using its network connection...this connection is asynchronous so I can lock both the DAC and Upsampler to the master clock (I use Naim HDX as the UPnP server). I would expect that if I had the transport...it would sound just as good on SACD or 16/44 based on what I have heard but I am unable to confirm..for now....this network connection is the best I have heard in my system.
I do have a Ayre DX-5 in my system which is likely the unit you used...and in my system..the USB input outperformed the transport on 16/44...but higher rez DVD audio and SACD discs through transport slightly outperformed hi Rez FLAC files of same material via USB. USB system was Mac mini/Ammara. I preferred the Naim NDS/PS555DR across all sample rates over the DX5 except SACD which I feel is best in native form. The best 16/44 playback I have heard prior to the Vivaldi stack was the Naim CD555/PS555DR which I use in my study system
FWIW...I still listen to vinyl more than 40% of the time and its my favorite source