I just came over from Android, and I have to say, I am on day two without a charge, where on my Android, I would get maybe a half a day. I know what people are thinking, I am not using my phone as much, but the fact is, I am using it just as much as I used my Note 3, which I have stated above, that I only got a half a day out of.
I've not used social media in months. And now I get almost three days of battery life with my 6 Plus. I mainly use Chrome, WhatsApp, BBM, and TapaTalk. From time to time, music, too.
One might argue that I don't really need a smartphone, but...