When you guys download these do you play them back at this high resolution from your computer, or do you convert from FLAC to MP3 (or something similar) and burn a CD?
For me it's PC to DAC at native resolution, up to 24/192 otherwise it would be indeed pointless.
Theoretically, if you run an ethernet cable you are also getting a direct copper link back to the PC that contains that crappy noisy switching power supply, which is isolated from the music system if your data stream is traveling wirelessly. Nothing for nothing.
Some interfaces have internal transformers for galvanic isolation but not very many from what I understand. I have not tried them but in-line
transformers are available for $150 that will completely isolate the line. I am going to order one and find out if it improves the sound. That doesn't get rid of the switcher in the PC but with low power PC's that can be addressed by a reasonable linear supply.
mike