[Duplicity-talk] How to use duplicity for local backup

[MRob]

Hello, I want to ask opinion about backup tactic please.

I found a backup system that using only rsync to a local server. A few 
scripts run on the server that create tree of historical directrories 
that are filled with hard links to the main rsync target. I never saw 
this but my understand of the benefit:
* saving space for historical backups because they only use inodes
* simple scheme to use rsync and ln
* But am I correct, to understand if a file *change* then the historical 
data is lost so its a shortcoming of the scheme.

Is this scheme popular? Is it useful in comparison to local-rsync 
variation of duplicity? For example, lower CPU needed because not 
creating archive files and encrypting them. Can duplicity have gpg turn 
off when it is not necessary? I prefer duplicity to replace the scheme 
but have limited storage and limited CPU cycles.

Could you guide to help make duplicity a comparable option in that 
context? Thank you.