Try this first (just read a comment on another forum about this), boot into safe mode and uninstall macafee bloatware, reboot.
Should be fine.
Edit: macafee is tmobile bloatware (so this will probably only work if you have tmobile)
I've been getting great battery life compared to last gen phones, compared to this gen I'd say it's a bit below average.
Very happy to see Android phones are finally performing well out of the box.