Jay, just prior to the 4.1.2 update AT&T pushed a OTA maintenance regarding wifi. Check advanced settings....its ticked wifi always on even when sleeping.
According to Samsung the explanation given for the decrease in battery performance compared to 4.1.1 is the 4.1.2 update and the maint update prior to the update.
A day or so prior to the 4.1.2 update I saw in the notification area, upper left the diagonal grey and red arrows similar to software update, and when I oopened notification window it said " connecting to "DNR" server" I had absolutely no idea what that was. I had no warning of any kind as to a update, and that pisses me off. This is my phone. I wasted alot of time trying to figure out what had happened. It was only after I contacted a data supervisor that they informed me that the "Anomaly" was a AT&T update. At minimum I believe they should have given some sort of heads up.
Both the maint and 4.1.2 have Impacted my battery performance. I have disabled all the att garbage, apps, and google+ notifications. It improved things but still not the same as it was prior to the 4.1.2 update.