I have stared having the same problem a couple of days ago. Though I have sync enabled 0-24 for 3 gmail accounts, motions are on, screen auto rotate is also on. I am using nova launcher, almost all Samsung apps are frozen and most of time I am on wifi.
Now, this drain has nothing to do with the stuff I just mentioned (Enabled sync, motions...). I have all that things enabled all the time, and yes MPU and GPU are OC to 1600 and 640 MHz. But I was always getting >= 24h with ~3,5 h of screen on time. As I already mentioned, problem started a couple of days ago. Only thing which comes to my mind is that I have played with freezing / defrosting apps and I probably installed a couple of apps too. Like Beautiful Widgets and that's my main candidate to blame for this at the moment.
Though I am still not sure... Better than battery stats didn't show anything what could help. Network location locator or similar is at the top of the list of partial wake locks. But the time it hold the lock (About 25 min.) can't be the reason for such a high drain.
I have switched to HD Widgets, what I was using before (With this app one can disable auto location.) removed Beautiful Widgets, and turned off'Use wireless networks' and GPS in location services hoping it will help... So we'll see...