Used it for a very long time, however there is one caveat; since it uses the filesystem directly to mirror all kinds of file attributes, your destination filesystem has to support them all (acls, fattrs, caps) and always be mounted with the proper options. Hard links are being used for deduplication. Same kind of caution is appropriate when moving a dirvish vault to a new disk or mount point. Make sure to have a suitable destination filesystem, all the proper mount options, and don't just use cp to copy it over.
These kind of problems are avoided by using tools like Borg backup, which store the backups in archive files which are independent of the underlying filesystem. On the other hand, if one such archive gets damaged, recovery from it is much harder than with a system like dirvish.
Make your choice :)
It looks like the project is looking for an administrator.
Looks very similar to rsnapshot: http://rsnapshot.org/
Both use rsync, hardlinking, are written in perl, and seem to have been around for ages. I've depended on rsnapshot for many years and have been really happy with it.
At a previous company we used this to shuttle Tbs of data about