I find it hard to return to this mix at times due to the amount of compression and perhaps EQing used during the creation of the Atmos mix. It's not an issue of loudness or abrasion, but rather, I feel it dilutes the strong tone of the instrumentation present in the mix. I also find that the kickdrum also gets lost amongst the band, which is one of the most important elements of the drum kit.
One thing I will say though: this mix is NOT a pointless one. Amongst two quad mixes, two previous stereo mixes (and the third new Zappa stereo mix), and the 5.1 mix, there was a palpable danger coming into this release that the Atmos mix would be another to throw atop the pile, with arguments about its quality amounting to the fringes of how this or that element is panned in the surround sound field. Instead, it's extremely playful, with instruments filling out the surround sound field. It's distinctly unlike how we heard the album before due to such adventurousness, with a few new mix elements to boot (like adding the scream to the end of "Highway Star").
On principle, I'm absolutely for presenting an album in a radically new way. With the original mix sounding as good as it does, a Steven Wilson "tweak this here and there" approach is absolutely not what I would have liked for this release. Zappa had something new to say with his stereo and Atmos mixes of Machine Head, and I'm glad he was able to say it.
The Atmos mix of Machine Head will probably go down as the most contentious surround sound mix of 2024. While I personally have issues with this mix, its level of ambition is a prime example of what will push the art of surround sound mixing forward for the days to come.