So often I see people on here stating that the S model iPhones are only a minor upgrade and they are going to wait for the next 'properly new' iPhone. It's actually the S models that introduce the major new technologies such as Siri, Touch ID and now Force Touch that actually change the way we use our phones. The new number models haven't had a major new feature since the iPhone 4's retina screen, it's always a new physical design with a new processor and the usual upgrade to the camera. The new sizes of the 6 were so new to iPhone users that everyone seemed to overlook the fact that there weren't actually any new features or technology. I always upgrade every year but I always think of the S models as the bigger upgrade.