I can't ask this question in an audiophile forum bcos it just causes a sh!t storm... audiophiles are usually literate, analytical and very passionate about their imaginary audio nuances.
I completely get balancing between components with AC 60Hz hum... but balanced headphones just seems to be a gimmick to extract money from electronically illiterate people, or crazy audiophiles.
I've ordered some equipment to confirm my suspicions, but I still can't understand how isolating the R/L return path is going to make any difference when the R/L amps share ground.

But I could be wrong, what's your take?