XLR-RCA-BNC sonic quality differences

The main thing about XLRs is the lower noise floor and less potential for hum. When used in a truly balanced system you also have the advantage of 6db more of gain. An XLR uses three conductors. The positive and negative have there own conductors and the ground floats above and below the signal.

I'm really surprised by the lack of answers here.

What I know is that BNC connectors with Coax cable seems to be impressive compared with conventional cabling when using the Dartzeel to Dartzeel combination.

Is that special to the Dartzeels, or is the use of BNC's with long runs of coax beneficial to other setups?

And, would a there be better results using conventional wire and BNC or XLR connectors?

For long runs I would think BNC would be a bad way to go because usually BNC connectors are used for video coax and it is the wrong impedence for audio signals.