Doug Schroeder has posted a review of the Silnote Audio Orion M-1 Master Reference ($695) and Epirus Master Reference ($995) USB cables at Dagogo. His conclusions:
“The Silnote Audio Cables Orion yields a warmer, less defined sound than does the Epirus. As copper tends to have a more lush, but slightly less distinct sound in comparison to silver’s tighter but brighter character, so also these USB cables follow this pattern. However, I have found that some cables with silver are harsh, while others are gentle on the ears. The Epirus, the one with silver conductors, manages a tricky feat of being supremely refined without excess brightness. I have come across very few cables of any sort that manage this as well. Other USB cables I have tested have the characteristic of a more “edgy” sound, but not the Epirus.”
You can read the full review here.