I consider value, camera quality for normal point and shoot, screen size and quality, weight. Handling.
I bought a 13 Pro refurb last year and was planning on keeping it for a while, sadly I can mostly use it, but some games are too small for my eyes on it, so I've decided to upgrade to a Max iPhone and based on my criteria think I've settled on the 15 Pro Max once its price drops, maybe when the 16 is launched.
I've looked at Max iPhones a lot before but held off due to their size. But the 15 is a bit lighter and I think easier to handle then other ones. Plus I get extended battery life.
And since having Pro Motion I can't go back lol. Hence the Pro range of iPhones being my option.