AES/EBU balanced XLR digital transmission vs. coax and I2S

I think it depends on which inputs the DAC manufacturer puts the most effort into, but I found running i2S from my Iris to my DAC to be notably superior to SPDIF. From what I’ve read AES/EBU sounds to be close to i2S in performance, but I haven’t compared directly in my system so can’t say. I’m sticking with i2S, but it should be said the HDMI cable should be as short as possible in that application as i2S degrades quickly with distance (my HDMI cable is 6” and no more than 1 foot is recommended). Some DACs are optimized for USB as well and Holo DACs come to mind there, so again a lot depends on how a given DAC is designed. FWIW.

What @soix said.  It also depends on your cables.  One advantage to AES/EBU is that quality cables are availble.  Machine made cables like I2S and USB are less available in high quality. 

There is no difference in sould based just on the connector.  It is the implementation by the OEM and the cable.

My Grimm streamer has only AES/EBU output so I'm sure they focused on that.

My Innous has only USB so I'm sure they focused on that.

Both sound excellent.

Jerry