This isn't a single update issue for me, I have been experiencing dreadful battery life ever since 7.0 was released. To say that these threads come about ever update, that may be so but it is a lot more serious than that for me. I have never had problems with updates from iOS4 right through to 6.1.4, it is since iOS7 that my problems started. I'm not an iPhone noobie and I always do clean installs via iTunes and not OTA. I have tried numerous methods to fix my problem, going even so far as to completely delete my iCloud backup. I have reinstalled iOS more than ten times, setting up as a new phone on each occasion, and my battery life is still woeful. Each subsequent iOS7 update has not made my battery life noticeably worse, it was the initial 7.0 which did it and there has been no improvement since.
So to hear these 'user error' and 'mine is fine, you're doing something wrong' posts is unhelpful. Something within iOS7 categorically does not agree with my iPhone 5 and it's a fact. Even when setting up as a new phone from a clean install and not downloading any apps, my battery life is a good 2.5 to 3 hours down on what I achieved with iOS 6.1.4