After Monster cables: Synergistic Research Ethernet Switch - Positive Feedback (positive-feedback.com)
"The Ethernet Switch UEF has dramatically changed my listening behavior. With it in place, I can now experience streamed music with something very close if not the equal of my very best local files. In some cases, I even prefer it over vinyl. There is now a more fundamentally correct amount of coherent attack, sustain and decay in the playback. There is a purity and lucidity that avoids fatigue and rewards timbral purity. All of this without the edge and grain that seemed to be the norm for most streamed music in the past. Bottom line. When streaming, I am now more emotionally connected than ever to the music!"
"This track will sound fantastic on any system, so I was amazed that the Ethernet Switch UEF could step it up to another level. The depth and breadth of the soundstage is outstanding regardless of source. When the bongos kick in, you will impressed by the superb dynamics and extended spatial cues."
It is a switch. Unless other gigabit switches are underpowered and couldn't move packets fast enough, there's nothing you can do at Ethernet level to make music sound better.