5" flagship phone? Seriously? Do they sell bigger hands with them?
I can barely use my S3 with one hand and i have big hands. Manufacturers are not bringing the most powerful stuff to smaller devices, they consider a medium-en feature to sport a 4" screen.
Any big phone user will note (excepting those with extremely big hands) that using the phone with a single hand can be a chore. To hit the back button i have to repositionate the (slippery) phone on my hand which is something that adds awkwardness and increases the chance of a fall.
With the new wave of quality and affordable tablets if you have to watch a vid o play a game, read a magazine, etc. you just get one of them. 4" is more than acceptable if you HAVE to read a news or play a game and do not want to carry a tablet with you, when commuting for example. Once you get home, hit the couch or bed with your tablet and you will enjoy a back-safe browsing/gaming/chatting experience.
We just do not need big phones anymore. I know my next phone will be a <= 4.2 inch. And i'd like to have the same features than the flagship device whatever size it it is.