Storage space gives me wood as well, and 1.6TB is too much.
I know some people say this is overkill, but there are a lot of features I was looking for, which this unit has.
I want FTP access, Easy Backup, Hot-Swapability, Network Access (duh), and RAID. A few other cool things about this is that the external USB devices can be added to the RAID. Also, if the drives are replaced (opening the device), your warrantee is not voided.
Overkill, maybe, but I need and will use all the features. My home environment driven by my consulting is growing fast, and I need to be able to keep up
Granted, I'm early in the purchase process. I'm trying to find a great deal, and may find a lower priced alternative, but this is the device I am leaning towards.