I asked this question, balanced OR unbalanced, of a well known equipment evaluator and review writer for Widescreen Review about this and here are his responses, paraphrased into one quote.
Balanced whenever you can.
Unabalanced only when you have to.
Noise = bad.
No noise = good
Telephony, data, network, etc are all differential. Why?
Inherently low noise, plus excellent external noise rejection.
I question cancelling even order harmonic distortion and leaving odd order distortion, but I don't have anything that could model it and prove it wrong.
Regardless, your ears (and mine) agree... balanced sounds better to me.