I have not yet tried a factory reset as, at the moment, I have no backup capability.
Stock phone, last OS 2.3.6, no extra UI or shell or Launcher or anything. Purchased 11/2011.
After applying the update the night it was made available to me, Thursday Aug 2nd, I charged it and left it overnight.
Using the Samsung stock Sense UI (that is Sense, right?)
The next day (after needing to recreate all my app folders and reorganize my pages, change a lot of settings, and get used to Swype's keyboard since the old Samsung-provided swipe-style board no longer is available and the new one doesn't swipe) I noticed that, by the end of the day, my phone was running much lower in battery than I would have hoped - down to 34% after a day of just texting with my fiancee. Maybe 2-3 an hour.
Saturday we went to the beach/shore/ocean. My phone sat in her purse in our beach bag, out of direct sunlight. It went from a full charge, to below 75% after a 90 minute drive, to 18% 6 hours later. Just from sitting.
This morning on my 18 minute drive to work, the phone went from full charge (I unplugged it not 30 seconds before I left the house) to 88%.
I tried popping the battery as had been suggested. I let it get back to a full charge. 30 minutes later, 84%.
So the battery thing didn't work.
One other thing I've noticed is that the GPS locator seems to be activating at all sorts of random times, though most of the time after I hit the Apps button.
There's no other apps open.
I've disabled the locator service for both my weather app and Moon Phase Pro.
Yahoo Messenger isn't signed in (and doesn't have a locator setting).
I've now disabled Wifi and GPS, and will see how it runs over the next hour.'
I'm used to being able to go all day without going less than 85% battery when just texting. If I'm reading e-books or playing minor games (Angry Birds, shh) it never goes less than 50% unless I'm doing it all day long. well, never previously went below 50%...
Thus far, I'm pretty underwhelmed with the update, and rather annoyed that I accidentally applied it.