The iPhone 6 Plus is just too big - as big as my hand. I bet, you can't sit down with this monster in your pocket. Stop making it wider and higher!
Not only it is implied apps should develop a specific layout just for it, but IIRC it also has a different viewport size which is not a multiple.
On top of that, the 6 already reports a new viewport width in the browser, which I guess it can't be helped though.
Android's much more fragmented and yet hasn't had any trouble making gains. As much as Apple and Apple-boosters have made of fragmentation as some great cost, actual market experience hasn't really born that out in terms of selling handsets.
It does make things more difficult for developers, sure.
For reference, I literally cannot use his phone one-handed; I can't hold it and reach all the way across the screen with my thumb. I'm a small dude and he's a big one, and some devices are just designed for the opposite extreme.
I have a friend with the note who actually uses a stylus with it. I don't get it but he really loves that phone.
I wouldn't buy it, can't carry it around - forget cycling.
http://en.wikipedia.org/wiki/Samsung_Galaxy_Note_Edge
151.3 mm (5.96 in) H 82.4 mm (3.24 in) W 8.3 mm (0.33 in) D
vs
iPhone 6 Plus
158.1 mm (6.22 in) H 77.8 mm (3.06 in) W 7.1 mm (0.28 in) D