I have done my own listening and measurements between TOSLINK and coax and I am happy with my preference for TOSLINK if the design is right. a TOSLINK signal is far larger in amplitude compared to a coax signal. So TOSLINK signals are easier to reclock with a simple schmitt trigger circuit. Supply noise has less of an effect on the actual signal from a TOSLINK socket. The noise would only affect the electronics inside the socket.
A coax signal needs to be amplified first from 0.6V to at least 2.7V. That can be an issue in a design.
There are also no earth loops issues with TOSLINK.