My issues after the Nougat update:Sometimes WiFi doesn't automatically reconnect to my home network.Noticably worse battery life, with battery stats not indicating what is consuming battery life.The update did toggle some settings, so I've been going...
Battery life is definitely worse, but not by a lot.Noticed a couple times it wouldn't connect to WiFi when I returned home.Otherwise seems smooth and no other glitches have occurred.
Try Aquamail for an email client. I use multiple accounts and it works great. Also very configurable for a lot of sources like aspects, including look and feel.Battery life seems as good or better than Marshmallow.