I was just browsing the thread and feel I must add my 2 cents. When I had PS Audio transport and dac, the I2s interface was clearly better SQ than any other formats.
I agree with above comments to have your router and any wall-warts plugged into a different line than your stereo setup. Also using a LPS (linear power supply) on the router instead of the SMPS wall-wart is a major improvement in sonics and removes noise.
@veemike Can you be specific about what is missing from your music playback or what improvements you seek?