I have had mixed results in this arena, depending on the equipment in question. From my Mark Levinson 380 to Mark Levinson 335, balanced sounds best, hands down, no questions asked.
From my Sony SCD-1 to the ML 380, SE used to sound better than balanced, that is, a $15 pair of AudioQuest cables used to sound better to me than a $500 pair of Madrigal CZ-Gel... And then I got new speakers that are a little warmer and more coherent, and now the Balanced cables, to me, sound better hands down.
This is doubly odd as the SCD-1 was designed to be single-ended, and the balanced signal is generated artificially...