Re:
Never understood the point of having balanced drive to headphones - well, it isn't really balanced to headphones is it? By their nature, they're single ended devices, so you need to convert to single ended before connection to the drivers, so all you're doing is adding an extra return wire by grounding either the hot or the cold line (the 'phase' or 'antiphase'. XLRs are posh connectors though - if a little inconvenient for domestic use.