Since this is Audioholics, digital is digital is digital (and I do not have, nor really want, any measurements that say otherwise). The only deciding factor should be durability as is alluded to by
@lsiberian above.
That being said, coaxial used to be the connection of choice for CD players worth their mettle (AES/EBU even better). According to most reviewers, a CD player that "only" had optical (or, God forbid, no digital outs) was not "serious".
These days, I prefer USB because I enjoy DSD files (I'm weird like that) and USB is just about the only way to get full resolution of said DSD to a DAC, which my integrated amp has. For TV and streaming video, I use the optical inputs out of necessity as I do not like how flimsy the connections are.