Looks like the battery problems are gone, at least for me and my SGH-i257M. I got a full 7 days from my last charge. I used to get 2 or 3 days.
I use it as a simple phone with perhaps a few calls each day. Occasionally, but not every day, i use the internet to check weather, do a search or find a location.
Not rooted. KitKat 4.4.2
Battery Doctor with most automatic options disabled. Location, BlueTooth, MobileData and Wi-Fi are turned OFF unless i am explicitly using them. Updates only by Wi-Fi which i turn on occasionally.
I have disabled all but a few of the built-in Apps as recommended by the CleanMaster AppManager, only keeping the ones that i need.
I have a 12000 mAh PoweRocks for trips where no plug-in is available. I get 5 charges from it before it needs to be re-charged. It needs about 12 hours plugged in to recharge. So i should be good for the best part of 6 weeks away from a plug-in.