I was by no means implying h1f1add1cted's choice is wrong.
For example in my hi-fi (sort of...) set, I am connecting the old, oops, vingate Onkyo R1 Integra CD Player to the Yulong D200 via optical, and it sounds so much better compared to the integrated dac.
I just wanted to know why he chose optical against coaxial and he gave an appropriate answer.
Also, not connecting both cables just to start switching and trying to chase subtle differences, instead on really enjoying music is a wise choice IMO :-)
Yes I never compared both in this setup, for example I use as transport my iBasso DX50 -> coaxial out -> coaxial cable -> coaxial in ->iFi micro iDSD and it sounds pretty awesome too in such a small package.