Originally Posted by Jester_rm 
Depends on the system, and I would think it's more common for a drive to fail than an enclosure (but anything can happen). Look for one that has user-replaceable drives...then you should be able to replace drives if they fail or put the old drives in a new enclosure if that fails.
Had a Maxtor external lose its way 5 months ago. Took out the drive and put it in a computer. Works fine. Just need to get a new case for it. (This was one of my backups for work so it's files that would cost tens of thousand of $$$$ to redo) Don't forget about offsite backup. You can protect your data, whatever it may be, by backing up to synchonized hard drive systems but what happens if your house is broken into. Or is washed away as we've seen in 08 and back in 98. Or, in Californeea, is burned or when the big one hits next month?
Back up to hard drives but also offsite. On one of the many sites out there. It's only about 50 buckaroos per annum.