if you keep only one copy of your files anywhere, you have a chance to lose them, no matter what you use.
my $.02… The best use for MBL is to do backups. Also, this is a NAS device, not a USB drive. There will be a learning curve if you never used one before.
Personally, for the price, it is one of the best Home NAS I ever owned…
Some fun reading:
http://howto.cnet.com/8301-33088_39-57556308/digital-storage-basics-part-3-backup-vs-redundancy/
