Mike
My understanding from what I've read as I haven't tried my Red with the Mk I is that certain cables are triggering something in both DS DACs that Ted thinks is the Pre-emphasis flag and other cables are not. I one owners case the cable he owned and preferred caused the issue but his backup cable did not. Won't know for sure until I try it myself and I've got four different I2S cables from three different companies I can try. But it will be a while as the DS Mk I is at another house in another state.
No one has reported any issues with any of their USB cables and what they have preferred in the past they still prefer with the Red. I found that to be true too between the Red and both the Holo and Aqua DAC.
Anyway if you decide you prefer the server then with the Out Of Stock notice at Kitsune which is likely parts shortage selling should be no problem for next to no loss. I bought mine for the most part as an experiment knowing I could re-sell easily but it will now replace an Aries Femto that is 6+ years old. Will just have to teach the wife how to use a different software package.