I started using Deja Vu years ago and liked it because I was able to make ad hoc, or scheduled backups of my hard drive (clone) or any other files or folders. I paid for it twice.
Somewhere the line, my scheduled backups would get almost to the end and then at the 11th hour get a dialouge box that the back up failed. I contacted support and they advised that I should make sure that my "SafetyNet Folder was not imbedded in the same folder as the one that I was backing up to. No problem... External Drive > Safety Net Folder, External Drive Backup Folder...
I tried manual ad hoc backups and the first one I tried worked fine. I set up schedules and then waited. I started having the same failures again. I want back to manual backups and found that some passed and some failed.
Finally, I just gave up on deja Vu. I am using Memeo which runs in the background and once it has initially made the first back up, makes incremental back ups on it's own. My system is running slow. I do not know if Memeo running in the background is responsible for this.
I am taking a serious look at Super Duper and CCC as I need CLONES no older than 1 month on external drives in the event something bad happens. Worse case, I buy a new machine, and combined with my latest CLONE I am back in business. I need at minimum WEEKLY of my entire home directory. Having these backup's to have the cabability of restoring anything in your home directory is just a comfortable feeling to have.
When time machine first came out, I used it faithfully. (with nothing else...(bad move to depend on proprietary software that you dont have direct access to files that were copied). Something happened to my mac and I thought no worries. I have my TIME MACHINE Backup. I went out and bought a new Imac. I discovered that the TIME MACHINE would not play nice with my new machine. Lucky for me I had backups on another hard drive which I manually backed up by dragging the contents of my home folder to another drive. "A la manuel" manual processes.
When the loss occurred, in between the time that Time machine would not play nice and the time it took to copy everthing onto the new computer, load apps, configure settings, load Entourage, reconfigure all the email settings, there is the shock and fear that you have loss 20 years worth of data and praying that your manuel backups will minimize the damage.
Ever since that dreadful day, I have gone overboard by some people's standards. TIME MACHINE, Backup software to make monthly clones, backup software to make weekly backups of home directory and just for grins, when the machine is not being used in the middle of the night, I use APPLE's BACKUP APP to copy a recent backup onto another drive that keeps 12 different copies and disposes of the 1st copy with the 13th copy.