Dealer perspective.
First we have purchased way more expensive etherenet cables then we have sold because we have heard the difference.
We have heard differences between AQ and Wireworld cables and we have heard differences between levels of these products.
On direct system connections there absolutely are audible differences.
The thinking that some people expouse ie bits is bits isn't the case.
We did one demo at a clients home all Naim system with an SDS server and swapped out one just one Wireworld ethernet cable and the sound stage got bigger and the overall clarity of the entire digital system improved.
The problem with the methodology of the above test gentleman with the youtube video, is I don;t hear him talking about listening I hear him using measurements.
If you think measurements can tell you the story in terms of what you can perceive you are way off.
Pour a glass of ripple, a glass of a good $20 bottle of wine and a $1,000 bottle of Chateau Lafeitt.Roschild into a gas chromotograph and see how much difference the test gear will tell you, water, organic compounds, machines can't tell the difference you can obviously taste the difference.
Do you want to know how we test?
1: Plug streamer into router or switch with standard cable
2: Play 1 min of a track
3: Switch cables listen to what changes
If you have a system with good resolution you can easily hear the difference.
Dave and Troy
Audio Doctor NJ