A lot depends ......if you have a good spdiff cable and a bad ebu....your not going to hear much. You need either the same type of cable or quality of cable to make the comparisons otherwise there are too many variables.
Some people (including some on this thread) are getting confused. S/PDIF and AES/EBU are digital formats (or standards). You can deliver either format over the same physical interface - optical, coaxial or XLR.
FWIW at one point I had both an XLR (aes/ebu) and COAXIAL (spdif) AZ MC2 cables. The coaxial sounded more "splashy", less sharp. The XLR was for me a definitely more preferable sound.