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No problems at all that I can think of. I've been updating pretty much every day and have noticed a couple of small issues (Bluetooth message support issue made BT go nuts) that get resolved pretty quickly.
Generally would definitely recommend it. Make a backup before flashing it and to be extra safe, take a peek at the xda nightlies thread. They'll discuss any issues/fixes as soon as they're apparent.
What version of CM are you running on it? I'm on CM12.1 nightlies and no battery issues at all at the moment, but the nightly from a week or so ago was pretty battery hungry.
I'd suggest downloading wakelock detector to see if anything's keeping the phone from sleeping. I think this needs root?
Also, the OPO's built in battery stats page should tell you the biggest battery hog.