More useful is a matter of opinion, both hard and soft links have very valid use cases but I usually create softlinks:
Directories
You can only create hard links to files and not to directories.
And then since creating hard links frequently fails creating softlinks has become a habit.
Back-ups
I have had issues with back-up software that does not recognise a hard link as such and then your backup might:
- store a full copy of the linked file for each hardlink rather than the hardlink.
and even when the hardlink was recognised as such restoring it can be a challenge as:
- the target of the hardlink must be still/already be present or the restore fails1
or when it wasn't archived as a hardlink:
- your restore will result in files that are no longer linked.