While it's definitely the best iPhone to date in most respects, a number of small issues hold it back from being the undisputed dominant phone this year.
Beautiful design; Polished user interface; Audio jack on bottom of phone; Larger "Retina" screen; Fast 4G LTE service
Lightning connector adapter MIA; iOS lagging behind Android in some areas; Screen is taller but not wider; Weak battery life; Poor Google services integration (and getting worse