One fly in the ointment here. Even if your system maintains correct polarity, recorded media doesn't. Many vinyl LPs and even some CDs are recorded in inverted polarity. Mostly it's the older LPs, but I've had some recent issues that were inverted. It's nice to be able to invert polarity with a remote, ;~) like I can with my phono pre. For CDs, if you have them archived on a hard drive a program like Pure Music will invert polarity for you if you tell it to in the comment box of the iTunes info file. Nice to have the automation there.
It's interesting why this business with polarity makes a difference. Air is a non-linear medium. Just look at the adibatic pressure/volume curves for air. The result is that the sound wave is distorted asymetrically. The peaks are compressed and the troughs are elongated if I remember correctly. This results in even order harmonic distortion, mostly 2nd order. Kind of like what a SET amp does. Inverting this will turn things around, elongated peaks and compressed troughs. So the difference.