agree but it will definitely not mean better or they would say. people complained about 6(not me) and they will complain about the 6S batt life
Yup. I'm one of the people wanting more battery life. An iPhone 6/6s with the battery life of a 6 Plus would be great and I'd pay at least $100 more for that but having seen the pictures in this thread I'm not going to complain too much about the battery life not going up with the 6s. At least now, having seen the pictures, I understand why. The haptic engine has taken space that was previously used for battery so after Apple's decision to include 3D Touch the battery capacity really did have to be reduced and the engineers have actually done a reasonable job of getting enough efficiency gains from the new electronics to preserve the existing battery life.
I'm afraid that the only options I see for a step change in battery life are...
1 - Some dramatic improvement in battery chemistry to get more mAh per unit volume.
2 - Apple backing off from it's obsession with thinness and adding 1mm or so to the thickness of the device to fit bigger batteries.
3 - A big innovation in screen efficiency. Efficiencies in the CPU/GPU/radios/etc are going well but a step-change in screen efficiency is conceivable (variable rate refresh, local LG-type refresh, quantum dots, more efficient backlight, new type of OLED, etc).
Until one or more of those come along I can't see a huge leap in battery life on the horizon. I'd love to be proved wrong though.
At least with iOS9's new low power mode those of us who care more about battery life than performance can permanently engage power save mode to downclock the CPU. My current phone is a 5 and I already find that more than fast enough for my needs, in fact I never had any issues with the 4. I'm 99% confident that when I upgrade to the 6s I'll be able to immediately set it to permanent low power mode and still be thinking "wow, this thing is noticeably faster than my old 5".