The stand-alone HD’s are like insurance policies - you should have one and you hope you never have to use it. You find out if you have a good insurance company when you put in a claim. So too with the external HD. You find out how well it really works after you’ve re-formatted your HD and need to put all the stuff back. If 4 years go by before you actually call upon the external HD to repopulate your computer and it doesn’t work - You’re screw… ! AND your warranty has expired.
It seems to me that a warranty should extend for 1 or 2 years (whatever is currently being offered) OR until a successful restoration has been performed - which ever comes second. The technology exists to track the usage of the drive, why not incorporate it into the backup HD? I also think it would make a great selling point.
What do you think?