Slide up the front panel of D-Link's ShareCenter DNS-325-110 two-bay NAS enclosure, and it's a snap to install or swap out a 3.5-inch hard drive.
Unfortunately, as of the current version 1.01 firmware, there's no support for drives larger than 2.2TB, so you're limited to a total of 4.4TB of storage until D-Link upgrades that firmware.
Beyond that, the DNS-325-110 is a very capable NAS box with an attractive HTML interface and lots of software features. Multimedia perks include iTunes and Universal Plug and Play media-serving, while remote access is available via HTTP and FTP. The operating system is extensible via apps that you can download from D-Link's site, including a photo album app, a blog publisher, a remote file browser and so on.
The DNS-325-110 has a single USB port on the back of the unit as well as a Copy/Unmount button. Though the button works well, the difference between copy (press and hold for 3 seconds) and unmounts (5 seconds) is a bit narrow. The DNS-325 offers both RAID 0 and 1, JBOD architecture and plain volumes. Alas, it proved only a mediocre performer in my hands-on tests, averaging around 30MBps writing to its internal hard drive, and about 49MBps reading it back. I had no issues streaming high definition video.
In short, the D-Link DNS-325-110 is a well engineered NAS box with a solid set of options. However, at its current pricing, it's impossible to recommend it over the faster QNAP and Synology (DS211+ and DS411slim) products with their superior feature sets and support for 3TB drives.