I would not use a switch. Will confound the analysis.
After both are broken in I would try one day one then one day another. Do that a couple times to see if there is some really huge difference. Then I would listen to the music from one for a couple weeks. Then switch, listening for a couple weeks. Do this a couple times and the differences at all levels should become obvious.
If you really want to understand the differences at all levels you have to listen to the music and not the equipment and the differences will unfold.