Mixed in here is the subjects of what you choose as test music, and what kind of music is critical to choosing a system. The wrong choices and you take your system in places where one kind of music and recordings get better at the expense of all others.
My big mistake was grabbing some electronic music CDs that I really liked. I kept optimizing the ethereal nature (lots of natural treble and ultrasonics (think planar speakers). But most music sounded worse.
Finally, about twenty five years ago I started listening to live acoustic music as frequently as possible… to calibrate my ear. Then the symphony a couple times a month. I then chose acoustic music for auditioning. My ear got trained as to what to listen for and the auditioning then drove very different choices in equipment… making most music sound better at every upgrade.. now if there is a chance for music to sound good… my system will give it. However electronic music sounds natural… not overly ethereal… which I liked… but the result is 98% or the music l listen to sounds simply incredible.