As others have said, the basic difference is the 11 Pro is a 1-handed device, the Max is a 2-handed device. If you want to be able to use your phone 1-handed the smaller one is the way to go. If you primarily use your phone for entertainment/media consumption the Max may be a better option. The battery on the Max is much better (by about 20-30%) too. A small detail but the Max also has a noticeably stronger Taptic Engine as well. Unfortunately iOS makes poor usage of the larger screen and there are no extra software features on the Max (multi-window, split-screen, etc.), so that is a major downside. The Max is also a lot heavier.