Disclaimer : With MY setup (7.2.2) with front height being not even 30 degrees to listening position, which is more within Auro specs than in Atmos specs.
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Dolby Surround upmixing : it brings the scene closer to the listening positon, too close to my taste. I then not listening to an artist, I feel I am within his head, I don't like it.
DTS Neural X upmixing : the scene is properly spaced, but there is too much front height use, like some engineers wanted to be sure the listenner will notice they are working. I am losing too much the spirit of the original stereo, it's more a total transformation than an ehancement.
Auro 3D : it sounds wider, but with respect to the original stereo mixing, the front height are here to make the sound taller, some says "the wall of sound". I really like this MORE than stereo as I it's stereo++. It's still well separated, but wider. It's still at the right place, in front of you.
So that's MY point of view of course. I assume it depends a lot about the listenner and the setup.
edit : fixed there are -> they are and point of you -> point of view XD
Time for another coffee
edit 2 : for Atmos music, after testing straight vs Auro 3D, the native Atmos / Dolby surround performs better than Atmos through Auro 3D. Which is a good thing to experiment, Atmos is great