If you think you are getting noise into your analog system via the Ethernet, I suggest you have a crappy Ethernet NIC so you are expecting magic cables to fix a bad design.
I’m sure I was getting noise from my Panoramic modem that the streamer is plugged into directly.
The magic Ethernet cable cost $130, came with a 60 day no questions asked return policy and absolutely sounded better than the $20 Belden cable.
No placebo effect, and my bias was in fact against the magic cable - I wanted to send it back.
Tomorrow I will be trying out a black-magic Ethernet cable to compare with the magic cable, also returnable.
Either way this was a low cost solution that didn’t require another powered device that I have no room and no spare outlets for.
Yes, there is abundance of snake oil in this industry but there are also plenty of really effective reasonably priced products.