Esoteric K-03X Runin RCA & XLR Outputs Separately?

I have a relatively new unit which I have run in one of the settings (no upsampling and no filters) using the RCA outputs. I wanted to compare my RCA cable with a different type of XLR cable. I am finding that there is some glare and harshness listening with the XLR cable. I am wondering would some of the differnce be due to significantly less time playing using the XLR output circuitry?

Thanks