I tend to agree, by training and by years of experience, that in the digital realm, if the correct information arrives at the other end within the tolerances of the equipment that handles jitter, 'fuzz' and other maladies that would appear if you looked at the signal in an analog sense, the information will be interpreted correctly by the receiving equipment. So, and especially for a short run, glass or plastic, no bottom line difference as long as the cables are in good condition.

The only choice I would debate is optical vs. coax. Again, it's not the medium of the transfer, it's what happens at the receiving end. Someone 'in the know' with regard to the digital protocols of Toslink vs. coax has said that the Toslink was a 'cheaply' designed system and that the coax would give a better data transfer, not becuase of the transfer medium, but because of the data handling protocol.

But then again, if in critical listening, you can't tell the difference, then choose what you like!