I prefer using Synaptic, to get a history. If something unexpected
should get broken, the history might help.
I make backup_archives.tar.gz and I don't sync the files. I always
backup the complete Linux and keep at least the last 2 backup archives.
It might be that I didn't notice that something got broken, so a synced
backups also could be broken.
I'll take a look at the wiki.