I found the AES/EBU cable to sound better than coax between my PWT and Bryston BDA-1, IF ground pin 1 was lifted at the Bryston and grounded at the PWT.
Otherwise, if grounded at both ends sound was somewhat poorer than coax.
I think the difference is due to the grounding of both chassis together with coax, and pin 1 connected both sides with XLR AES/EBU.
Only pin 1 lifted on the XLR AES/EBU leaves both chassis uncoupled groundwise. Shield on the AES/EBU is grounded at the source device (the PWT in my case) as it should be.
Otherwise, if grounded at both ends sound was somewhat poorer than coax.
I think the difference is due to the grounding of both chassis together with coax, and pin 1 connected both sides with XLR AES/EBU.
Only pin 1 lifted on the XLR AES/EBU leaves both chassis uncoupled groundwise. Shield on the AES/EBU is grounded at the source device (the PWT in my case) as it should be.