Screen resolutions...
OK, so the iPhones will sell, no matter what, but If Samsung or HTC or Microsoft or almost anyone else released a brand new, flagship phone with less than 1920x1080 it would be lambasted as archaic, could have tried better or not as high a ppi ratio as an iPhone...
now that the 6 has some odd, low density display and the 6plus makes do with 1920x1080 its all good and more than anyone needs....
as for sapphire... Lenovo has a 5" smartphone with a sapphire glass display....