I've upgraded every year since the 3GS.
There are three reasons I may not this time:
1. I have absolutely no problems with my 6+. I love this phone...still
2. AT&T Next. Usually I sell my old phone and buy a new one, but unless I pay full retail, by monthly service will go up at least $15 per month. I upgraded my wife's phone (she wanted a 5S) in May, so I'm already paying extra.
3. Aside from force touch, stronger frame (supposedly), and 2GB of RAM, what else will Apple add? I have Applecare+, so if my phone ever bends, I'll just get a new one.
Don't get me wrong, I WANT a new phone, but I really can't justify it.
Although, my wife says my daughter needs a phone as she's going to high school this year. Maybe she will end up with my 6+ (in an Otterbox case as I don't trust her not to drop it) and I will get the 6S+...maybe....
You forgot the camera...
- Stronger, stiffer
- A9 (new process, so either a powerhouse, massively better battery time, or a bit of both (the usual tact))
- Potentially a higher res screen, if not GPU performance will be much higher than curent phones
- 2 GB
- New Camera
- Force Touch
- Mystery upgrade... (often there is something we don't know that gets sprung), using haptic feedback would be interesting.