I don't think I've noticed a significant improvement or decline in my battery since the update.
However, I've had issues with voice calls the last few months - the other person can barely hear me or not at all. I went and filled out the online form on the Google site and asked for a callback. Within 2 seconds of submitting it, I got a call.
They want me to do a factory reset and if that doesn't work, just reply to the email and they'll send me a new one.
Damn their service is good.