Sound Quality of Cables Used With Bluesound Node

I would go with USB!

Optical (Toslink):

• Pros:
  • Uses light to transmit data, eliminating electrical interference.
  • Ideal for connecting directly to a soundbar or AV receiver.
  • No electrical noise transmission.
• Cons:
  • Limited bandwidth (usually up to 96kHz).
  • Not suitable for high-quality surround sound formats like Dolby TrueHD or DTS-HD Master Audio.
• Verdict: Good for simplicity and avoiding electrical noise
•  
• Coaxial (RCA):
• Pros:
  • Greater bandwidth (supports up to 24-bit/192kHz audio).
  • Tends to sound better than optical due to higher quality.
  • Commonly found in AV receivers and integrated amplifiers.
• Cons:
  • Potential transfer of electrical noise.
  • • Verdict: Offers better audio quality than optical¹.

  • USB:

    • Pros:
      • Sends digital data directly.
      • Widely used for computer audio interfaces.
      • Supports high-resolution audio formats.
    • Cons:
      • May introduce jitter (timing variations).
      • Depends on the quality of the DAC (digital-to-analog converter).
    • Verdict: Suitable for computer-based audio systems².

  • In summary:

  • Coaxial tends to provide better audio quality than optical due to its higher bandwidth.

@ellajeanelle +1. USB transfers the heavy lifting to your outboard DAC.
With coax/spdif you will benefit more when you have a great clock in your network player and the BS Node isn’t famous for its clock/processing. 
With that said, personal preferences and system synergy comes into play - so try both the coax and USB and see what you like best. I would not waste time on toslink. 

I agree.  go usb.  I think when I had a node (long ago) they didn't support USb and that was the only time I used coax (reluctantly, but better than optical).