I phone 6s can be said to be as the best phone available in the market irrespective of the os. It has the best chip that is the a9 processor. And the best design statment. Its camera performance can easily compete with any phone in its price range. And as the cherry on top is its 3d touch display. Which sences the pressure applied on the screen. There are very few problems with this phone but are major ones. Example- its price and its battery backup.