Nice system and room.
My technique for evaluation is to do a couple quick comparisons, back and forth, just to see if anything sticks out.
Then to get serious. Put the on new thing in and leave it for a couple weeks… absolutely paying no attention. Let your subconscious experience the music. Then, swap back the old one… and go back to listening to music (not for changes). You will become aware during listening to the old.
I find swapping to the old is the most telling, unless there are huge differences. Write it down. Listen for a week or two… switch. You should be able to sense and describe really subtle differences this way.
Unless there are big differences… quick A - Bing is hard. Your minds eye has one specific focal point… you have to flit around perceiving stuff… but listening to music let’s your subconscious (~ 95% of your brain power) assess the sound in its entirety.