On headphones (Senn HD600) I got to the point that I could differentiate the 2 tracks 80% of the time w/o looking, but had a hard time picking a favorite.
On speakers, I prefer B to A. A sound as if it was recorded from the front row with 2 dimensional sound between speakers and forward at times. B sounds like was recorded from a distance and the instruments seem to sit in 3D space from the speakers back. More "air". But I have old ears.
Win7>JRMC>USB DAC>AES DJH tube pre>Cary Audio CAD572SEII tube amps>Soliloquy 5.3 speakers