I own both silver and copper and there is no obvious difference that I can tell. Idk about all this flavor stuff. I don't think it's worth the cost unless you diy the cable and even then, still probably not worth the money. Youd be better off tube rolling with a tube amp than paying that much for cables to try to change the sound.
The original cable is a piece of junk construction wise, so worst case scenario is a pre-emptive strike. In my main audio system, there are clearly audible differences between copper and silver interconnects so I decided to see what gives with the HE-500's. I already have loads of tubes to roll.