Measuring 423 by 285 by 43 mm (WDH), the DSM-320 has a similar form factor to a home-theatre component, such as a DVD player. In contrast to digital media receivers that are styled more like computer gear, the DSM-320 will easily blend into a home-theatre rack. The device is entirely silver-gray except for a translucent, black plastic strip that spans the width of the front panel, covering a couple of blue status LEDs. With the exception of a power button, the front panel is devoid of controls; you must operate the DSM-320 with the remote (a bummer if it gets lost). Because there's no front-panel text display, you'll have to switch on the TV to navigate the device -- that's a downer if you just want to listen to music. Another drawback: the DSM-320 doesn't display album art.
The midsize remote has a full array of buttons, including the requisite four-way keypad plus Music, Photo, Video, and Online media buttons that shortcut to the primary media navigation screens. Although the remote has Page Up and Page Down buttons, scrolling through long track lists can be sluggish. What's more, even though the remote has an alphanumeric keypad, you can't simply jump to a file by pressing the first letter of its name; instead you must press Search to open a dedicated search screen. Otherwise, the TV-based interface is generally clean and fairly easy to navigate.
Two separate PC applications can be used to stream files to the DSM-320 from your hard drive. Windows XP users with the Service Pack 2 upgrade can use Windows Media Connect (a free download) instead of D-Link's Media Server application, which isn't compatible with rights-managed WMA files. I recommend choosing one or the other, however, as simultaneously running both makes using the DSM-320 somewhat more of a hassle.
Using the Windows Media Connect server with the DSM-320, you can play MP3, WMA (rights-managed and non-rights-managed) and WAV audio files; MPEG-1, MPEG-2, and MPEG-4 video files; JPEG, BMP, PNG, TIFF, and GIF image files. The DSM-320 doesn't support Windows Media Video (WMV) files, nor can it play protected AAC files purchased from iTunes Music Store. Although the Windows Media Connect server is documented as supporting only WPL (Windows Media Player format) playlists, I was also able to play M3U (Musicmatch) playlists with it. The Rhapsody application must be running to enable streaming tracks from the on-demand music service, which sells subscriptions for US$10 a month. It's also worth noting that AOL Internet Radio is supported.
Connectivity is a strong point of the DSM-320. Unlike most digital media receivers, the D-Link includes optical and coaxial digital outputs in addition to the requisite analog outputs. And while the 320 sports a component-video output (in addition to composite and S-Video), it can't output high-def video or photos like the Roku HD-1000 can. More impressive is the DSM-320's support for wide-screen (16:9) and standard (4:3) aspect ratio televisions. And although the DSM-320 has integrated 802.11g wireless networking, it also includes an Ethernet port for wired networks.
I tested the DSM-320's chops with rights-managed WMA music files purchased from both the Napster and Musicmatch stores. The device played the files without a hitch. My video test files and photo slide shows also played smoothly and looked sharp. I was easily able to start a photo slide show, then select musical accompaniment for it. Because the DSM-320 utilises the 802.11g standard (as opposed to lower-bandwidth 802.11b), the bandwidth is adequate for playing most of the video files that might be kicking around your PC's hard drive. Of course, your network's individual peculiarities may mean that everything -- including the DSM-320 -- won't work at optimal speeds.
The unit suffered a couple of frustrating problems that rendered it temporarily inoperable. For example, when set up about 9 meters away from my wireless router with a couple of walls separating the two, the DSM-320 sometimes had problems finding the server after booting up and occasionally dropped an established connection or crashed. A few times it even went into a loop, rebooting continuously until I yanked the power cord. Replacing my SMC router with a D-Link model seemed to largely alleviate the snags.
At its best, the DSM-320 is a world-class contender. At its worst, it's downright exasperating. Although the unit is highly affordable and has tons of cool features, I'd like to see it guaranteed to work with a wider selection of non-D-Link routers and access points.