I laugh at "audiophile" Ethernet cables. Miles upon miles of dicey coax cable, to a consumer-grade cable modem in the home, likely connected to a consumer-grade router...and some pricey cables for that last meter or two of length from router to the component. Within the home network, the router could very well be the weak point, although even Cat 6 is far greater than any bandwidth we'd ever use to stream audio or video data in the home. Even without the fancy name (and silver plating) on it.
The way the Ethernet standard works, packets either arrive intact, or they don't. If not, they are sent again. And given the data rate, there is plenty of time to resend those packets and still have everything in sync by the time the receiving equipment processes it.
Cat 5 vs. 5e vs. 6, etc., is determined mostly by the tightness of the twisted pairs of wires. A tighter twist means greater common-mode rejection of external noise. Shielding would be needed if the cable were in a very problematic location (lots of EMI/RFI), with packet loss so high as to be unusable. Cat 6 is already theoretically 10x faster than most network cards in use today.
The only thing that upsets me is that I didn't think of "audiophile" Ethernet cables first. For that matter, I should gut some ancient Linksys routers, stick them in expensive cases, and pawn them off as "audiophile" as well.
The sad fact is that few (if any) of the typical customer Audioquest goes after would have no clue about network protocols, data transport and the OSI model. (It even gives
me a headache to think about it.)