The backup option in the settings seems to back up just the system settings: some of those get synced to other devices on the same gmail account.

So when I powered up my N7 and entered my gmail password for the first and only time, it then instantly had all of my calendar data, contacts list, WiFi SSIDs and passphrases, and a few other things.

I don't know how much of that was just "Google Sync" versus the "Settings Backup". And were I to wipe my phone and then "restore", I don't know how much additional stuff would come back.

??