I have been using an iPhone since the iPhone 4 and have never switched. I was pretty impressed with the iPhone 5s and then the 6s in terms of innovation and now the 7 plus stole the show.
The dual lens camera is amazing as when we zoom on a normal phone, the image quality is affected but no more on the iPhone 7 Plus as it has a separate telephoto lens ! It is water resistant too and iOS is amazing as always !