If there is a audible difference between 2 digital cables it simply means that one of them is not doing it's "job" (could also be your devices).
There is no "warmer sound", "more depth" , "more whatever" in digital audio. All you need is to have every send bit being received correctly, once you reached that goal there is nothing more to achieve even if you spend a fortune on your digital cables.
Maybe if you spend $1000 on a ethernet cable your video and audio streams will improve.
Ethernet cables are really cheap cables and most them manage to transmit 250Mbit signals (that's nearly 100 times faster than S/PDIF) on each twisted pair without any packet loss.