It's not big enough. Imagine 5 years down the road when your shooting a 40+ MP DSLR and each picture is 90-110MB each!
I plan on keeping mine on HDDs with backups and swapping out the drives whenever they go bad... Storage is only getting cheaper.
However, when this thing would be worth it is if you wanted to save a select number of pictures, drop the device in the drawer, and then forget it until you're 85 years old when suddenly you remember and pull it out... But then you find out that USB has long since been discontinued and you can no longer plug it into your computer.
Just a few things to think about. Don't take any of it too seriously.