I'll copy and paste what I put over on Headfi.
"I picked them up today and my early impressions are amazement to say the least. Excellent build and to my surprise, comfort. Features are top notch if you have Apple products. Sound is very clear, detailed, and open, with an excellent bass that goes deep but is very controlled. Noise cancelling is at the very least right up there with Sony and Bose. I feel it may even be better but since I'm not flying right now I can't fully test this. The mic for calls is top notch just like the AirPods Pro. And the Transparency mode is by far the best I've heard on a set of over ears and it's not close. The Spatial Audio on iPhone and iPads is nuts. You can take the Max plus an iPad on the go and have a convenient portable movie theatre setup with you. I believe these headphones are going to shock a lot of people. Especially the "overpriced" camp."
To further clarify sound quality. I would say the AirPods Max are comparable to the Dali iO-6 Wireless ANC headphones with a touch more sparkle and excitement to them than the Dalis. The Dalis are a little smoother and laid back. The Dalis retail for $499 but are all sound quality and battery life. It's a very barebones product with a mediocre ANC and horrible transparency mode. It literally has no other features. The Max are comparable in sound (I prefer the Max), are more comfortable, has more features, better ANC, better build, and are just flat out more fun to use.