Talking about battery life:
I have IP7 as work phone ans SFx in my pocket also ,

If not used IP is superior , like for weekends .
If really used I can use IP' s battery in one day and in bad coverage areas , IP is eating battery like wolf. I was some weeks ago travelling by train , usef SFx for internet and IP7 for calls ( work) in the evening both almost died. And after all I used SFx for net maybe 4h and IP7 for talk one hour during day.
The problem is power saving , but if really used like bullzoser , I would not like to pay for IP7 my self.