It seems like the exynos version is vastly superior in terms of battery life at least from Ars testing
http://arstechnica.com/gadgets/2016/03/samsung-galaxy-s7-and-s7-edge-review-the-galaxy-s6-2-0/
http://arstechnica.com/gadgets/2016/03/samsung-galaxy-s7-and-s7-edge-review-the-galaxy-s6-2-0/