USB sucks! It doesn't surprise me that another input sounded better. Not sure what people think they are going to get out of a dedicated music server over a nicely setup server running Roon? You should not have any server in your music room or you shouldn't use usb, so that relieves any pressure on getting a particular server that is more quiet or has a better usb setup. I used to use the AURALiC Aries years ago and that software (ds lightning) was far superior than any other music server at the time, both SQ and GUI. But when I decided to get a great dac with ethernet, then there was no need for the AURALiC and my system sounds better, easier to support and setup, and much simpler.
If you add external disks to any of these servers, how are you going to backup this disk? How about restoring this disk? How about replacing the internal drive? If you look at the user manual, there is no reference to any of these questions, but this is true for all proprietary music servers. I like AURALiC overall, but you can do the same functions with the same sq and the same or better functionality for a lot less and you have the right dac.