@elizabeth do you have isolation transformer or other power conditioning device in your system? I use Torus AVR30 wall mount (I live in 240V country). It was only after I have the SA-10 I know the true capability of my system.
My SA-10 is in its second week. I don't think the break in has completed but it's sounding better and better. In my experience, playing discs directly using SA-10 transport gives the best results followed by a high-performance USB thumb drive. My hard disk player (Sony HAP-Z1ES) is not up to the standard of SA-10. While the Sony supports gapless playback in all formats, the sound is inferior when using SA-10 USB Audio input. I think to get the best from USB Type B input, need a much better player/streamer costing close to SA-10.
I wish SA-10 supports gapless playback when playing from USB drive. Right now it mutes with relay clicks at the beginning of each track which is annoying. I hope Marantz will fix this through firmware upgrade.