Like most things in audio "it depends". With my equipment (Levinson #36 and 37) XLR is definitely better. I've had the best results with Cardas Lightening and Audioquest Falcon. I've not had as good results with Illuminati Orchid. With other equipment this would likely be different. With analog interconnects in general long runs benefit from balanced (XLR) runs, due to the 2 hot poles running out of phase and effectively creating a noise cancelling process that reduces the effects of EMI and RFI. However, different equipment performs very differently, balanced vs single end. The original topology of the equipment is important. If it was designed as a balanced topology throughout, then the balanced should sound better. Some equipment is not designed this way. It may have balanced connections available, but is really single ended with the balanced being added for marketing reasons. In these cases the balanced should not be as clean sounding as the single ended.
