I have no problem with 5 inch, given screen shatters no matter which size I keep it in a man-purse. My style of using these things puts bigger screen equates better, assuming battery life improvement goes hand in hand. I have trouble single-hand operate even 2 inches, I need hold it pencil-pad 2 hands, and that could go as big as 5.5 inch no problem.
Apple clearly lose out on screens along; Retina Displays a UK reviewer put it a Googlized DPI number and it is pitiful compare to top of the line Androids (MHO is actually other way around; RD pretty much defines human capabilities and higher is just waste) smaller screens, wrong Aspect Ratios and size (10 inch is too big for one hand), and many other unrelated wrongs I can attribute to Apple iProducts.