My wife’s 14pm had 9.5 hrs with aod on, surprisingly went to 13hr of sot after turning it off.
I had 12 mini, 13mini, 13.
13 mini was a huge improvement over the 12 mini. It easily added 1.5hr sot for me while being the same size.
13 added another 1.5hrs of sot over the 13 mini.
What i noticed is that new iphones are power hungry and battery consumption is not linear - meaning that if you scroll non-stop instagram or web, you can get 10 hrs on 15 pro, 9 hrs on 13, 8hrs on 13 mini, 14 hrs on 13PM, 13hr on 14PM, 13.2 hr on 15pm when new and fresh.
Now here comes the difference: if not used actively, then the inefficiency kicks in. For example if you are not glued to your phone and spend a day normally checking your phone, then battery drops quite significantly and spent on idle.
For latter scenario(sitting at work), you can get 6-7.5 hrs on 15 pro, 5-7.5 hrs on 13, 4.5-6 hrs on 13 mini, 9-10 hrs on 13PM, 9-9.5 hrs on 14PM, 9-10 hr on 15pm when new and fresh.
For AOD eligible device you can shave another 2 hours from above to get the real life SOT when turned on.
In conclusion, the pro max seems to suffer the least in our experience because of the sheer amount of Mah available and it drops the least or maybe drops the same, but it just has higher ceiling and can afford to lose that (14hr nonstop SOT vs 9-10hr of inactive use).