I’m a one-handed phone user. When I’m home sitting on the couch, I couldn’t care less about the screen size, but when I’m walking on the street or in the car (stopped at a light or pulled over, of course) size matters. I want to be able to look up anything with one hand, quickly and easily.
I’m not interested in the iPhone 6. Aside from the improved camera (which is always the feature I’m most excited about), there’s nothing about the 6 that I want—especially the screen size. I suspect the reason there is no 4" iPhone 6 is because the new thinner design would mean no room for an adequate battery. This is a shame, as I am not the only person I know who still prefers the smaller screen size. I would accept a slightly thicker phone than the iPhone 6 in return for a 4" screen. The thickness of the iPhone 5s is fine.
Will the market prefer a smaller screen someday? I think so. In fact, I wouldn’t be surprised to see a Samsung ad with copy like “Introducing the Galaxy 7Slim—usable with one hand” to get in a little dig at Apple. Yes, I know Samsung makes smaller phones, but they compromise on performance and features, so they aren’t talked about much and they don’t sell well. Samsung and other Android makers could do themselves a favour here. They could sacrifice design a little bit (something Apple generally isn’t willing to do) to fit an adequate battery to sell a full featured, performant 4" smartphone.
Will Apple make a full featured 4" phone again? I’m skeptical, but I’m still hopeful. There’s a limit to how thin phones can get, so hopefully Apple can produce a full featured 4" iPhone with enough room for a suitable battery again.