Be careful, there's a string over on XDA about this and it killed my Note. I was rooted but otherwise stock GN2 (stock rom and recovery, apps, etc). Got the update, rebooted and it got stuck at the boot logo. I tried everything. Flashed CWM, then tried a couple different ROM's. Then went to TWRP recovery, and tried the Team Elektron ROM, that got a little farther, boot logo with sound, but it still hung. Tried a modem update, and even the bootloader - nothing worked.
Luckily I had just bought mine ($300 on Amazon right now) so I just sent it back as defective and ordered a new one. Gonna be real careful of the ATT update and maybe even skip it and go right to a custom ROM.