Famoej, I haven't listened critically to the mini-Toslink vs USB, but I have used both of them on the same computer. I switched to USB because my toslink connection at the computer became unstable and would frequently result in a transient static-like sound with minimal movement of the computer or Toslink cable.
Again, I haven't done a critical A-B test, but to my recollection they sounded at least very similar, save for the little glitch with the Toslink connection itself.
Since your DAC can handle both, it won't cost you much to hook up both and see what works best for you.
Hope that helps.
Michael
