External backup to tape

Hi everybody,
in my company we would like to schedule an additional weekly backup job on a tape device, in addition to ZeXtras backup. My first idea was to simply copy the "backup" folder that ZeXtras uses, but it contains a lot of different files, and the copy to tape device took about 21 hours.
So I searched on the wiki, and found the External backup feature: if I plan with a CLI script a weekly External backup to the tape device, the backup process would be faster?
Thank you in advance.