Take it with a grain of salt, but my opinion that the MW75 may be better is putting 2 and 2 together. So I read a couple of user reviews on Reddit that stated that the PX7 S2 is better in sound than the H95. When I read one of the publications that reviewed the MW75, can't remember which one, they stated that the MW75 was better in sound than the PX7 S2. Nothing concrete, but that's how I came to my conclusion. I've also seen a few reviews state that the PX7 S2 and Momentum 4 sound better than the AirPods Max. If this is indeed the case, then based on my experience comparing the H95 and AirPods Max and pretty much ranking them in the same tier of sound quality, that also leads me to believe that he MW75 will be a step up.
Also, Flossy Carter, a popular headphone reviewer, has the MW75 ranked as his favorite wireless ANC headphones for sound and build. He has ANC ranked high as well which is contradictory to some of the reviews out there. Now he's yet to rank the PX7 S2 or 5909, but he has the Momentum 4, which he loves, ranked lower in sound quality than the MW75.
None of this is concrete and I won't know for sure until my MW75s get here on Friday. But at least you now have an idea of how I came to my educated guess LOL.