I don't have the Pro Max yet, since I'm not ordering it until October. However, I am disappointed to see in online reviews that the same issues that make the portrait mode problematic on my 12 Pro Max and on the 13 Pro/Max are still significant problems with the 14 Pro/Max. This review (which seems pretty fair overall) highlights what I'm talking about:
How are your results with portrait mode?
How are your results with portrait mode?