After 6 months my iPhone 15 Pro Max is still at 100% battery life. Cycle count at 111. Battery life is amazing- I sometimes get through two days use on one charge, and I'm limiting it to 80% charging.
No scratches at all yet, touch wood, despite no screen protector. Aside from being such a big lump, it's almost perfect. The cameras are annoying for me, though, as there's three of them but none with a focal length as useful as all my old iPhones.
The action button I use just like the old switch- to silence notifications. It mainly serves to make it more difficult to use the volume controls, and I still frequently hit the wrong one. So, yeah, it's primarily an annoyance. No button and no switch would be better than losing easy control of the volume buttons. If Apple cared to give it any useful function they'd allow us to double and triple press it for different uses we could customise.