There are two sorts of backup.
One is a Backup, which backups up files which normally get modified (and you can select additional ones if you change something non-standard). This is quick. You can (normally) restore this over a fresh flash of an image.
Then there is an ImageBackup, which produces a flashable image of how your system looks at the moment. This will take several minutes to complete. (Also, if you try to schedule one on a regular basis it wont work, as the code that was added to the Backup side to fix it has never been added to the ImageManager side).
Neither backs up recordings.