Sony have now released the User Guide for the Z1.
You can get it from here.
A built in Backup and Restore tool. That looks mega handy!
It will be handy but obviously shouldn't be thought of as a 'total' backup solution.
It will not back up any data from installed apps, as in game data or files and folders.
For a complete list of what the Backup & Restore app does see below:-
Backup and restore application
Use the Backup and restore application to make backups of content to a memory
card or a USB storage device. Such backups can be used to restore your content
and some settings in cases where your data gets lost or deleted.
Types of content you can back up
Use the Backup and restore application to back up the following types of data:
Separate names with a comma.