Ethernet Cables, do they make a difference?

I have a Purist Audio Design CAT7 Ethernet cable running from an Orbi satellite into an Antipodes DX3 music server. The difference from the "stock" ethernet cable is discernible. If someone couldn't hear the difference in my system I would question their hearing acuity. They might not think the difference was worth the money (BTW I do) but the difference is present. For those that insist on demanding the double blind test before proclaiming what they themselves hear, nope I didn't do one. But, I also know that I routinely experiment with other changes to my system (cables, isolation, hi rez files, power conditioners, etc.) and I readily admit when I can't discern a difference. If I'm imagining the difference, then it is a really good investment for an enjoyable imagined experience.

On the LAN datatransfer is usually limited by the network cards of two connected devices. Most oF NAS do not support 1G.
If any of the devices in your LAN route from the storage of your audio file to your playing device is 100M - your entire connection is limited to 100M. Any cat5 cable will serve you as good as the most expensive cat6,7,8,9,10 whatever number you can come up with and willing to pay for.
Do yourself a favor and run a couple of tests:
1. Time one audio file copy over the cheapest network cable you have and compare it to the time of copy over the most expensive one. I bet they will be the SAME, and much less than duration of the audio track - conclusion: network is not a bottleneck.
2. Copy the same file file over to the playing device (computer or whatever) and compare playing it to playing from NAS. I bet you won’t be able to tell the difference.

Alternative approach - do the blind test and try to guess if cable is cat5 or cat<$$$>.

For strong believers: I’m selling cat13 network cables $111 per foot, custom made, special order... <Sarcasm>

Buy a Belden cat7 cable it has better bandwidth then a 6  thicker conductors and 2x shielding isolation.    They provide more wire to professionals than any body in the industry.
And they verify their results.

I went from a cheap cat5 Ethernet to a moderately priced Synergistic ethernet bought used (def the way to go). I had a 15-foot run and wanted to make sure I had good shielding and connectors for that length of cable exposure. I heard a small improvement- I interpreted as less shrill or grainy at the high end. For a couple hundred dollars I got perceived sound improvement and a cable that for sure is less susceptible to RMI RFI. So maybe piece of mind was all I got, but sometimes that’s all I need. 

A dealer explained that upgrading an Ethernet cable ONLY helps if you run it through a splitter box (any one will due). 

Ultimately, these things have to be tested with one’s ears. The guy who is content with just a lo-fi iPod should stick with that (even though even he would hear a difference when compared to hi-fi).