4" IP5 is just weird. 3,5" perfect size for a small portable device.
Those who want larger screens actually want small portable computers. It's a marketing thing anyway... phone, tablet, ultrabook, less and less difference every year.
Here's what I'd do:
iPhone nano 3,5"
iPhone mini 4"
iPhone 4.5"
iPad nano ~6" (with phone option)
iPad mini ~8"
iPad ~10"
iPad pro ~12" (MBA11 without keyboard with iOS/OSX mix)
Maybe too many products for Apple's taste, but that's what they have/had in iPod and Mac - mature product lines.
That's a great product lineup.
If Apple wanted to please customers instead of telling them what to like, they would do this. It's brilliant.
You want a tiny iphone? Get it.
You want a big screen iphone? Get it.
It's something for everyone
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I do know what I'm talking about, and no I don't wear skinny jeans.
I tried a friends S4 in my pocket, and for me it wasn't comfortable in my pocket, especially when sitting down.
I have to agree with him, men's pockets aren't small.
I wear dress pants to work and my Galaxy s III with an Otterbox fits very comfortably, as does my coworkers note 2