Regarding size, keep in mind the changes in Android will make it easier to use the phone with one hand despite the larger size. The floating action button in m

Regarding size, keep in mind the changes in Android will make it easier to use the phone with one hand despite the larger size. The floating action button in material design places important, frequently used action within thumb's distance. Android's use of the back button is also beneficial for larger screens, since back is an extremely common action and keeping at the bottom of the screen reduces reach distance. There will definitely be cases when it will be inconvenient to have a large screen (in fact personally I'm disappointed it's > 5") but the problems can be alleviated by software. You can see it today by switching back and forth between Android and iOS. iOS design has not yet adapted to the larger size and is more inconvenient to use one handed (for example, the swipe to go back gesture is not universal and exiting dialogs often requires hitting a "Done" button at the top of the screen.) But as the software changes the size will become more acceptable.