After about 2 years of heavy usage, any iPhone battery will misbehave. My 2 years old iPhone 5 barely made it to the day my 6s Plus arrived. Now the 6s Plus is wearing down some. I'll probably buy a new battery and wait until next year to upgrade.
This latest update made me sell my iphone because I can not go back to 10.3.1 and I do not want to stay with the back-up battery in my pocket. Soon I will sell and ipad for this too after the update goes like a hell. Conclusion, Apple has done it. I hope you guys have better devices. For me it's over. I'll pass Surface to my tablet and Android on the phone.
Every few months, or whenever I get a new "10.X.X is available" notification, I come on here and find the battery threads to see if Apple finally fixed whatever is killing battery life in iOS 10. Every time I make it through just a few pages of recent posts with continuous complaints and ultimately stay away from iOS 10 on my SE for at least another few months.
I don't know man, staying behind 1 iOS it's ok by me (that's what i did myself), but staying 2 iOS's behind is too much and not worth imo. ios 11 is almost here and now ios 9.3.5 almost belongs to the past...
You might be happy running ios 9.3.5 still but your phone will be definitely OLD in a couple of weeks....
and if you went back far enough you'd find threads on IOS 9, 8, 7, 6, etc. killing battery life. Because some people think they have a problem doesn't mean there is one. Stay where ever you want but I'd guess 99.99%+ of the population isn't having a battery problem.
Yeah personally i can't conceive running still my old ipad air 2 with its original ios 8.1 firmware. I've never had a single issue updating all my Apple devices (ipod and ipad) to the latest available ios version.
However with my iphone 6s i opted to stay on ios 9.3.5 for 11 more months. Why? well i still remember my Galaxy S3 and their original firmware performance, 2 years later a firmware update just killed the battery made it completely slow and useless.
Anyways as i said ios 11 will be here next month and i found completely pointless staying with ios 9 now.