Bluesound Node Best Sound Quality Input

What are the differences in audio sound quality one experiences when using optical, coaxial and pc-usb cables with the Bluesound Node? Does one hear significant  differences? I have the Node 2i. The rest of my system includes a Rotel A14 Integrated amp, Kef R5 speakers, Kimber Speaker cables, Kimber Coaxial and Optical cables and Audioquest cinnamon pc-usb with an audio quest power cable into the Node, and a PS Audio power cable into the amp. All plugged into a Panamax 5510 MC Regenerator. I hear a sinificantly improved sound with the pc-usb cable. Comments please.