I finally did a factory reset of my phone on Monday after the KitKat update, and thought that I would share my experience. As background, my phone was having a definite loss of battery life that seemed to coincide with the update. I also noticed one other issue: my phone kept prompting me for my PIN code to unlock even though I was connected to a trusted Bluetooth device. Other that that, my phone was running fine after the update, but I know that it is commonly advised to factory reset the phone after a named Android update, so I decided to go ahead. Here are some observations: - first, my phone is stock. It's never been rooted. - to describe my backup procedures, I use an app called SMSBackup+ to backup my text and MMS messages, and my call logs, to my GMail account. I also use an app called DropSync to backup important folders from storage to folders on my Dropbox account. This made things pretty simple to get back - everything was restored from the cloud. - when setting up I chose the option to restore my Google account. This worked *pretty* well, but not perfectly. My wallpaper returned, my WiFi options all restored, and may other settings were restored (screen timeout in display, for example.) However, Google Play restoring all of my apps was frustrating. The Play Store app kept stalling, and, after a few hours, I finally gave up and manually installed my last few remaining apps. - This was the first time when restoring from Google that some third apps had their settings restored. Not all apps did, but many of them did, and certainly more than half. This was nice to see. (Maddeningly, GMail was one app that did not.) However, I still had to visit every app just to make sure, and it restored a few apps that I had previously uninstalled. - Restoring from DropSync was great. I have folders for ringtones, wallpapers, etc., stored in a media folder on the phone - that all came back. My PocketCasts folder with podcasts all restored. My photos and videos all came back, and a few apps that have export/import settings options all were quick to get back up and running by importing the settings. (This goes for DropSync itself.) - Even though my SMS messages and call logs are backed up with SMSBackup+, I chose not to restore them. Having these in GMail folders for reference is good enough for now. - For the first two days, battery life was not better after the reset - it was as bad as it had been before the factory reset. I finally discovered that it was DropSync itself that had caused the problem. Without remembering, I had set up the sync of the PocketCasts folder shortly before the KitKat update hit my phone (probably because I was anticipating the update and wanted to make sure that PocketCasts was backed up in case the update went badly.) On Tuesday, when I realized it was the syncing that was causing a lot of drain, I changed DropSync to work only while plugged in (which is fine with me, as I do this every night), I found that battery life was basically the same as it was on 4.2.2 with the same usage. - The problem I mentioned with trusted Bluetooth devices has been solved. I only have to enter the PIN on restart, and when the trusted BT device has definitely been disconnected (even if it is then reconnected.) - I also took this time to encrypt the phone. This requires that you enter a PIN (which can be different than the unlock code) on each restart. Other than that, I notice no decrease in performance and, if there is an effect on battery life, it is negligible. - I've also chosen to start using Hangouts for SMS. I'm not wildly enthusiastic about it. There are some things about it I like more - receiving MMS messages with multiple images no longer creates those dumb slideshows, but instead shows just the images. It's also pretty easy to see who is part of a group message. Otherwise, it doesn't seem much better or worse than the stock messaging. I rarely use Hangouts for messaging anyway, so it's basically just a SMS app for me. Based on my experience, once I realized that it was DropSync causing my battery drain I probably would have been fine without the reset. The only advantages I can see is that trusted BT connection now seems to be stable again, and I was able to go through the steps I would need to do if I lost my phone, needed to have it replaced for warranty issues, etc.