Digital RCA vs AES/EBU connections

I've made a few comparisons like this, and even though my eyes & brain prefer the aes/ebu standard connection, the rca imho sounded better in most cases.

AES/EBU should be more transparent.

I have always found digital AES/EBU connections to sound relatively thin in the midrange. I have also found that using BNC or true 75 ohm RCA connectors is a significant upgrade if you use the coax connection.

I have not made comparisons, but I know that Forsell prefers its bnc connector, even using RCAs with their supplied adaptor, to AES/EBU, and that when I upgraded my Audio Logic dac and asked them to add another RCA jack for my 24/96 transport, after discussing it with them I had them replace the AES/EBU connection with the new RCA, because I was told that, properly implemented, it is a better digital connection than AES/EBU. I also recall Gene Pope of Pope Music telling us at an NJ Audio Society meeting that he felt the AES/EBU connection was an inferior one (although he felt that the S/DIF interface was clearly superior to all others). Given all this, it might be a good idea to see what the manufacturer(s) of the equipment you're using recommend; it could be that they have optimized their unit for a particular connection.