Rene Ritchie, iMore:

Almost 9 out of 10 AT&T cus­tomers bought 4-inch or smaller iPhones last quar­ter rather than all big screen Android and Windows Phones com­bined, and roughly 6 out of 10 Verizon cus­tomers did the same. So aside from geeks who keep post­ing about how they really want it, and shop­pers for whom big­ger as a fea­ture is always bet­ter, Apple might not feel any press­ing, main­stream need to add another screen size to the iPhone prod­uct line. Yet.

Apple’s focus on mak­ing a sin­gle great smart­phone is one of the rea­sons why the iPhone is suc­cess­ful. But the aging world­wide pop­u­la­tion with less-than-perfect eye­sight prefers larger icons. This is a huge mar­ket and it might be dif­fi­cult for Apple to ignore.

iMore reader SockRolid:

And wouldn’t it make sense to use the new leading-edge tech­nol­ogy (pos­si­bly OLED) on the normal-sized high-end 4″ iPhone 6 and later? Because that’s where every cubic mil­lime­ter counts. An OLED screen would elim­i­nate the need for LED back­lights, and could reduce bat­tery size require­ments. Because OLED pix­els plus IGZO con­duc­tors should be dra­mat­i­cally more effi­cient than LCD plus amor­phous silicon.

OLED has a power con­sump­tion advan­tage over LCD only when view­ing video. For every­thing else OLED con­sumes more power. Another chal­lenge for OLED is res­o­lu­tion: Mass man­u­fac­tur­ing 300+ ppi RGB OLEDs is dif­fi­cult at the moment. And one last thing: The iPhone uses LCDs made with low tem­per­a­ture poly sil­i­con or LTPS, not a-Si.