Here's my standard comment on the issue of coaxial or optical toslink connections: optical does require a conversion from electrical to optical signal, but it is also immune to RF and EM interference - which can be a very good thing over long runs or in environments where the cable must run parallel to speaker and power cables. You can break an optical cable, at which point you'll start to lose data and have obvious problems - so you don't want to put a right-angle bend in one, but that sort of treatment isn't recommended for any of the cables we find ourselves putting into our equipment racks.

In my experience, I've not been able to conclusively find a difference between the two when everything else was equal.