To be fair, this isn't really an Ethernet cable since apparently only two conductors are used. It's a proprietary "Denon Link cable. But it's still just an RJ-45 carrying a digital signal.
Now, I have no doubt that this is a very fine cable. The "high-purity copper wire" was probably refined from the choicest recycled stolen air condition coils. The RJ-45 plugs may have been hand-carved from optical grade polycarbonate, and the jacket hand-woven from spider-silk by master craftsmen high in the Peruvian Andes. But I have to wonder at the claim that it "will bring out all the nuances in digital audio reproduction". Nuances? In a digital signal?
So, like an ordinary cable will only deliver Ones and Zeros, but this cable will allow you to hear the subtle nuances between 1 and 0, such as 0.125, 0.33 and 0.972 ?