While i'm on a NOTE II from Sprint, I experienced the exact same thing.
Battery life was very good from the beginning which was early this Spring. battery life was (more than a day 30 hours, to a day and a half), and after tweaking settings and installing Battery Widget Reborn (mostly for night settings) battery was fantastic (2 plus days over 50 hours, mixed use). I've had both BWR and GSAM loaded for a while now and am familiar with what used what and when and could easily experiment with tweaks and apps to see what used juice. that was Android 4.2.....
... Then came the 4.3 update, pushed and installed it. Well that started the problems: the battery life simply collapsed to very comparable to what Margie is seeing (< day) and more importantly with (according to GSAM App Sucker) the same functions using the li,ns share of resources (android system, media and kernel, none of which were big users before). I also ran into the sudden high utilization by seldom used chrome, but that seemed to end after a few restarts following the 4.3 upgrade. SO i'm wondering if and when 4.3 might have been installed (or not) on Margies phone, and whether the drop in battery life/increase in draw was as a result of that. P.S. over the five or so days since the 4.3 "upgrade" i have tried, so far largely in vain, to recover the battery life i used to see on 4.2 . I've made some progress and now have over a day, but just barely (and that is using night mode for the overnight). also, if i use it more than light-moderately, i won't make it through the day. Hope this helps