I amended my original statement to the, “in most cases” as I have read that a few people have installed this with TWRP (not sure how.) I have tried flashing this through both JB system versions 9.16.6 and 9.16.9 with TWRP, while the OTA does download, what occurs is the device powers down> then boots into Recovery to install the update. However with TWRP installed the installation ends, I did not check to see what would happen if I mounted the system and flashed the OTA through TWRP recovery, as it seemed redundant and not worthwhile. The only way that I have been able to get the OTA to run has been with Stock Recovery, what I have noticed is that if the OTA is installed through System updates which this is done by downloading the update and selecting Install once download is available, if for any reason the OTA fails then there will not be any notification of what failed, should just see the dead android. If you are having difficulties with the OTA I would suggest, first making sure that you have Stock Recovery, check the system version for this: 9.16.6 = 9.18.79 (50.13mb) 9.16.9 = 9.20.1 (48.11mb) What I have done is I have linked both of the updates under the system versions above. Whether you have Root, are Unlocked, or do not have Root, if there are errors in flashing these updates, then they can be flashed manually through the Stock Recovery. Start by downloading the above, and copy the update onto your SD card (do not place in a folder.) With the update stored on your SD card, go ahead and Reboot Power + Volume (-) down> as soon as the screen is Black/Blank hold Power + Volume (+)> press the Volume (-) down button to “Recovery” once highlighted press the Volume (+) up> on the next screen you should see the dead android as soon as it appears hold the Volume (-) down button and quickly press the Volume (+) up button> this will launch you into Recovery, just scroll down with Volume (-) down and highlight the install from external sd card and press the Power button, look on the SD card for the appropriate file, highlight, and press Power. What I have noticed is that if for any reason the Update fails, there will be a reason given as to why it failed, which this is not the case with Updating through System Updates. The common errors that I have seen have been related to apps, whether it was the Acoustic Warning, or the Backup Assistant, or even the Calendar, it seems that this update does a thorough job of reviewing the system apps. With performing these updates, whether an error message is received or not, the way to confirm whether the update was successful or not relies on 1) the System version that should be either 9.18.79 (most cases) or 9.20.1, the 2) is to review the Baseband radio: VANQUISH_BP_100730.081.64.09P = OLD RADIO VANQUISH_BP_1007220.127.116.11P = NEW RADIO Also check the build date which it should reflect the date of “Sat May 25” Imo> the 9.18.79 is a more stable update, while all attempts that I have made have failed to some degree, my last attempt with 9.18.79 has ended with me acquiring the New Radio, so I’m done.