I use Sony A7 II and have one original A7 as a back up to that one. In practice battery life has been of little concern, and is no reason to stay away from Sony. In fact the EVF allows for less chimping, since you can see the exposure in real time.
I compared weight and size of a Sony A7 35mm format system to a Fuji X-T1 APS-C system, and found the difference to be small, so I decided on Sony 35mm full frame mirrorless.
The image stabilizer (IBIS) in the A7 II is a definite advantage.