I haven't tried XM4's or XM5's but I do have both XM3's and AirPods Max. The XM3's have excellent cancellation and are more comfortable, but have more of a bass-cannon sort of sound profile compared to the AirPods Max, which have cancellation almost as good but have a generally more balanced sound.
I'll have to play with that some. I knew of it but assumed the EQ was done on the phone rather than on the headphones, which if true kind of renders it moot because I use my headphones on several devices that the app doesn't run on.
