There is a trick I use for very noise environments, get a pair of very comfortable ear plugs, then put the Airpods Max over my ears with ANC and just turn up the volume a lot more. It's just tricky to get both sides to the same volume, if one ear plug is inserted a bit more then that side will end up quieter. But no outside noise will come through.
That's a great trick indeed, and it even works with cheap non-ANC headphones if you don't mind annoying people near you.
I used to do that when flying at the back of the plane with bargain-basement ANC headphones. It was quite effective, since you're basically stacking a second layer of sound blocking on top of the first layer (the ear cups)
and the ANC.
The major downside is that, unless you buy fancy concert earplugs, they don't block all frequencies evenly, so whatever you're listening to is not going to sound very good, and the high frequencies get really muffled. It can also get loud for someone sitting near you, although if the environment is noisy enough that's probably not an issue.
All that said, the AirPods Max ANC is so good that I don't even bother with that anymore--flying has become an almost disorientingly quiet experience, and I've been genuinely impressed with how much background office noise they block (which is what I bought them for).
In answer to the original question:
I have both APP2 and APM, and use both at the office and when flying.
The noise cancelling is very similar; I sometimes do a little better with APP2 since they're easier to get a good fit on for someone who wears glasses, but once I get the APM on right they block at least as much sound as the APP2. I think on planes with constant, low-pitched, quite loud noise, they're about the same; at the office when it's people talking getting blocked, the APM do an even better job, but not dramatically so.
The audio quality on the APM is noticeably better, but the APP2 are already quite good so I admit I only really notice if I'm listening to music in a quiet environment. Spatial Audio is similar, I'd say a bit better on the APP2 for head tracking, and a bit better on the APM for 3D positioning when you're
not moving your head.
The APM are however heavy, and I at least do notice it. If I'm leaning back and not really holding my head up (like on a plane) it's not a big deal, but at my desk I'm certainly increasingly aware I'm wearing them after a few hours, and I avoid putting them on at work when I don't have to. The band is comfortable, but my head is also on the sensitive side and I do start to feel it after a while, but then the APP2 also get uncomfortable after a few hours.
One APP2 note, I bought memory foam tips to replace the silicon ones. I actually think the silicon ones were more comfortable (they feel "lighter" and don't put as much pressure on the ear canal), but the silicon irritated my ears after a relatively short period of time, enough that I actually had skin peel if I wore them too often. The foam does block sound better than the silicon, since it fits tighter and conforms better, which is a bonus.
