I updated my Lumia 720 to Windows Phone 8 Update 3 Preview last week, and the device seems to be running quite well so far. I had the Amber update for 3 weeks before that and most of the earlier issues seemed to have been fixed in that release itself.
There are a few noticeable new features in the Update 3 Preview:
- Ability to close open apps from the task switcher (long press the back button to bring up the task switcher and then use the close button)
- Driving mode when using selected Bluetooth devices – it can start automatically based on your movement speed
- Screen rotation lock
The update does not seem to have affected the battery life for me, and the device seems to be pretty stable over the past week. The screen freeze issue still happened at times, but it seems to be triggered by the Facebook App. I uninstalled the Facebook App a couple of days back and the screen freeze and random typing issue seems to be gone.
Instructions on how to install Update 3 Preview on your phone for free without a developer account:
- Sign up for App Studio
- Download the Preview for Developers app on your device
- Run the Preview for Developers app and Enable the option
- Go to the phone update section of Settings and check for updates
- Update 3 Preview should be automatically detected and installed
Note that the update cannot be rolled back and Amber\GDR2 update is a prerequisite.