I'm a hardware whore, and the S7 Edge, really is hard to beat. Plus I get a major boner from big batteries
The S7 Edge is very compact for it's 5.5" size, and a massive 3,600mAh is almost unheard of now a days for a high end flagship phone.
I'm a big Nexus stock Android fan, but after owning my Note 5 for six months now, which is rooted, and tweaked, I am pleasantly surprised by Touchwiz on this phone, it doesn't bother me one bit now, and with a Material theme and Nova it practically looks like a Nexus, and I get amazing battery life 5.5h to 6h Screen On time, and the phone has no lag, and is buttery smooth. And I have all functions on too, nothing major disabled.
It's funny but everyone raves about stock vanilla Android, being such a lightweight OS, and very minimal system resources taken to run a Nexus. But weird thing is, these Nexus phones never seem to get great battery life, just ok or pretty good battery life. The Motorola Nexus 6 has a 3,200mAh battery, and the Nexus 6P has a huge 3,450mAh battery, you would think both those phones would be towards the top class of battery life, but even my Note 5 with just a 3,000mAh best them in battery life. Even official reviews, with fresh stock phones, typically shows the 3,000mAh Note 5 getting the same or slightly better battery life than the 3,450mAh Nexus 6P. Point being, put a 3,600mAh battery in a new Galaxy device, a la S7 Edge, and I think we may have Android battery champ.