I've decided it's too subjective to matter.
@copper and I have run frequency sweep tests, I have a background in mixing/mastering music, etc. - the Gravity (and the Air before it, but especially the Gravity) is one of the most responsive and widest soundstages in any vehicle. Moreover, it is extremely consistent and can be very flat if you want it to be. But it absolutely highlights the crappiness of a crappy source; you will
hear the compression.
I love it. Others won't. I hate Tesla's sound system. Others love it.
I prefer the Audio-Technica "sound," and Grado's. Others like Sennheiser or B&O.
It's all subjective. I'm sure they're both great.