While one is obligated to do a quick A/B or two, just to check for glaring differences. After that. I recommend maybe a week of listening then switch for a week. Try not to listen to the speakers... just listen to the music. Then try to forget when you swap them. This will bring out the real differences... this longer term comparison shows the big differences... in overall presentation, tonal balance.
If you do quick A/B you will use your minds eye (ear) to focus just on one instrument and sound type at a time... it is so limiting and is incredibly confusing. Best to do long term switches and the differences will become very obvious.
Good luck.