I very much appreciate how you're handing yourself with all the pressure to "see the light" (no pun intended) from the geek-sci-techies . None of us here is an audio expert, though. The beauty of digital is that it has no affinity to a certain type of data. It doesn't care one bit (I'm trying to watch the puns here) what the data contains -- a video stream, an internet chat, an audio stream, a forum post, etc. It's all made of of just two components: 1 and 0.

I agree that toslink isn't the most secure connection available, and glass/plastic fibers are very susceptible to damage from kinks and tight twists, but undamaged, properly connected, and used within its limits, the data gets there the same as it would over copper.