Ha ha ha, advice from analysts who time and time again get their predictions wrong. Not just a little wrong mind you but mindblowingly wrong.
4" - 4.3" is the sweet spot, if Apple wanted to double their sales figures they would give the phones away like Samsung/Blackberry etc do on 2for1 deals and discount handsets heavily for carriers.
This of course drops Apples margins and counters any sales increases made. Assclown analysts.