I ran it through its paces with a simple backup of a folder and it’s contents and the mirror backup worked well. Whatever was in the source file appeared in the target file after the backup, regardless of the state of the target file before the backup. This looks like it might replace Karen’s Replicator, which I used for ages but it started to fail for no apparent reason. I’ll see how it stacks up to sync-toy, which I shifted to after Karen’s Replicator. I do like that it can back up files and not create an encrypted blob.