The Buffalo TeraStation 5200 is a fast NAS with a solid chassis, combined with a practical display. It also comes with nice features such as iSCSI, a link to Amazon S3 and an integrated connection to security cameras, all of which make it an interesting business-oriented NAS device. The ability for remote access via BuffaloNAS.com is also interesting for business users, and home users as well. For the latter, DLNA Squeezebox Server and Bittorrent are welcome features.
Downsides of this NAS are the lack of extra apps for adding more features and functionality, and how you sometimes can't see everything in the firmware. It's also a bit of a shame the Buffalo TeraStation 5200 is not available without disks. If you need more features than are available here, for a bit more money you can get the Synology DS712+ or TS-269 Pro from QNAP.
The Buffalo TeraStation 5200 2TB costs an average of £447, and comes with 10 licences for the back-up software package NovaBackup Business and three years of factory warranty.