There's an article now in softpedia "battery drain issues 6.1.3 become epidemic".
As for me, yesterday I bought a Mophie Juice Pack Plus. I've been using the phone since 4am pretty heavy and it's now 8pm. I'm at 40%.
I was at 20% at 2pm and charged it to 85%.
This is the only way I am getting a good full day of usage.
I also don't believe in turning off features as a fix.
I did experience an issue a few updates ago where the "Setting Time Zone" service would check all the time. I turned that off but apple fixed that.
Other than that I don't believe in turning off 3G, or data altogether. Or have to turn off push or iCloud or Siri etc etc to get a decent battery life. What is the point in having a smartphone if you have to turn off all the features in order for it to work properly. Nonsense.
The iPhone should at the very least give you a full 1 day of full use with ALL the features turned ON. Of course, I turn off wifi because I'm never on wifi; but as far as the features that make this "smart" and not just a Blackberry Curve, I have them ON. As it should be.
I bought this case just so that if Apple never fixes this battery problem; then my wife can get a full day of use and I can move on to a Galaxy S4 then.
I'm an Apple guy. I have a MacBook, but if this is how is going to go, then ill get something else.