If the hard disk dies with the content on it you'll have to redo the videos again. It's just a fact of what happens when hard drives fail. You can use that device to get whatever was on the drives back to your system providing the drives power up and you can gain access to the information. That device would do well if you needed to move files from one drive to another and didn't want to mount them inside the case or you didn't have enough space to put additional drives inside but I wouldn't depend on it as a final solution for adding additional drive space to your rig.
 
In either case if the drive fails chances are you won't recover the data stored there.