My impression so far is there is a very subtle improvement in tone (slightly smoother highs and a bit tighter bass) and separation of instruments.
I have a DH Labs ethernet cable but it’s coming directly out of a Cox cable router and I am sure that if I used an optical or other decent switch it would make zero difference.
I’ve ordered a SmoothLan and will compare.
Lastly, I had no expectations but it is a zero risk tweak that I can return and then say it did or did not work for me in my system.
@mikhailark
Even if you are skeptical, which everyone should be really, you could start by understanding what these products "claim" to do - which in this case has zero to do with recovering lost bits.