I work for one of the major cell phone carriers and am having the same issues as you on both my ipad mini with retina display and my iPhone 5s. It seems like every other update fixes it then the next one ruins it again. I am not a heavy user at all and my phone just sits in my pocket doing nothing and the battery drains. I normally get over a day out if my phone, but now I'm lucky to get 8 hours. My iPad used to go 5 days with what I do on it, now I'm lucky to get 2 days and it's turned off most if the time (that blows the "turn it off for 2 days theory right out of the water!☺). Clearly this is an Apple issue with the software. I have literally had every iPhone up to this point since 2007 (with the exception of the newest models and the 5c, and have never experienced this issue. Here are a few of my observations:
1. You should not have to turn off Wi-Fi, Bluetooth, etc. Your phone is designed to use these effortlessly and you should not have to remember to turn them off and on all the time.
2. Yes, you should close down the apps you are truly not using, but the ones you use often SHOULD be left "open" as it takes more battery and data usage to open them every time you are using them. That is more of a multi taking area for most users.
3. My battery should not drain 20% just by checking my email, my bank account, and my local newspaper before I get out of bed.
4. Good luck everyone, I'm awaiting the "fix" this time and hope they don't mess it up again after they do fix it. I miss getting almost 2 days out of my battery and am tired of my customers complaining to me about it.