My device is not rooted (purchased in March). The update was through the Samsung notification - automatic (except for saying proceed). The update went smoothly - no error messages. However, after update, the Nook app would not open so I uninstalled the original and reinstalled through Google Play. In addition, the home page was changed, Samsung putting back on the Media Hub and removing all of my personal folders - icons (very irritating). The standard weather app and calendar widgets were larger than original after update (pushing the calendar off into page 2), so I removed and added the G0 Weather app (I have since removed it to see if the Tab will shut off - it still needs 2 shut downs. As I mentioned before, after the first shut down, the tablet keeps a slight glow for about 20 sec., then goes black, then immediately restarts (as if during the glow something is happening??). On 2nd shutdown, glow is for 5 sec. then off complete.
I prefer not to root (yet) but am uncertain how to proceed with factory restore if I have updated through Samsung. Might it not just reload a faulty OS? As I mentioned, wiping the cache did not seem to work.