I'd never heard of them either but $10 PER YEAR for a single computer with unlimited data??? Sounds too good to be true!
And certainly too cheap to pass up!
So I signed up - all pretty straightforward - and it looks pretty good. You don't even have to give your credit card details, presumably until a month's time when the trial period is up.
But already I have noticed one enormous problem: The backup software effectively mirrors your own computer. You can choose which folders to include and exclude etc, but what it does it makes a mirror copy of the things you include.
The problem is, if you remove something from your computer, it gets removed from the backup. So it's basically fine if what you want to protect against is recovering your data if you computer is stolen or if you have a hard disk failure or whatever. But its no use if you find you have a file missing because you accidentally deleted it months ago: you won't find the file in the backups either!
There's another, potentially more serious problem. If you have your data on an external USB drive (as I do) then you just check the folders on the external drive that you want backing up and all is well. I have Dupplica backing up my 1.5TB of data as we speak... which is going to take a while! Like maybe a week.
But here's the thing: If I power up my Mac with my external data disk unmounted, Dupplica will assume that data is no longer there and it will go about deleting the backup. I haven't tested this yet obviously, but it may be that a simple dismount of your data disk will effectively wipe your back up! And then you need to speed another week uploading it all again. This would indeed be a show-stopper.
For this reason, I think I will remove the Dupplica app from my startup items and just run it when I want to, rather than have it sitting there running in the background all the time. I'll do some tests to confirm how it works, but deleting the backups simply because an external drive is not there, does seem a bit of shortcoming!