Glass Toslink Optical versus Plastic

Any real world audio advantages, if any, to using glass as opposed to plastic.

I'm sure with great distances such as miles of fiber optic cables certainly matters.

But what about a couple of feet?

So far, I've read that DD, DTS, and the like benefit the most due to high bandwidth needed for multichannel audio.

But is bandwidth in the MHz region really needed for use in a dac that is being fed a 16/44 pcm signal via toslink? Or even a 24/192 signal?

If so, and if you have heard the difference, please elaborate.

BTW, I am feeding signal from an Apple A.E. to my dacs' optical input, whereas my reference player feeds the dacs' coax input.

Would really like to hear from those who are using or have used glass before I order one for my iTunes stream.

I may want to compare it also to the coax in my player.

T.I.A.