Well, I have a n810, the latest upgrade showed up in App Manager last night so I flashed it. it seemed to flash fine, got to the rebooting stage, showed the home page, then kept on rebooting, and rebooting, and....
After a while I got tired of watching it flail around, so I took out the battery (the only way to stop the rebooting) connected the tablet to my laptop and flashed from the beginning.....essentially following the same steps as above.
This time there was no rebooting loop, all my apps got reinstalled fine, and all my data and files are back in place.