Retrospect used to be something I have used for years because it offered the ability to restore not just a deleted/corrupted file, but be able to restore the complete machine if need be. However, because it refuses to work with most Blu-Ray drives and has issues with hanging, I have to find something else. Retrospect was nice because one could save a backup stored on an external hard disk to DVD media for long term archiving.
I prefer a backup program to do the work as opposed to a sync utility, because a sync utility will propagate changes should malware like CryptoLocker hit a machine. A backup program will almost certainly have a previous version that isn't ruined available, assuming there is enough disk space free on the external drive that older backups with readable files are not deleted.
I also like being able to restore from a complete image. There are other utilities out there for backups, but I'd like to see about opinions what others are using before trying them out. Genie is one, so is NovaBackup. However, other than ads, I've not read many honest (i.e. not paid for) reviews.