Priced at $80 (as of 11/24/2009), the Roku SD set-top box brings the cost of streaming media from Netflix, Amazon, and other Internet on-demand services to a new low--but it also reduces the video resolution to DVD quality (as opposed to the high-definition capabilities of the more expensive Roku HD and ). In addition, if you're depending on Wi-Fi for your network connection, the Roku SD restricts you to the slower 802.11b and g network speeds, which can also affect video quality.
But on a legacy analog set or an HDTV with a good scaler for standard-def content, the lower resolution doesn't have to be a deal breaker, especially if you can hook up the Roku SD through its ethernet port. In my tests on a 42-inch HDTV, I had problems only when I used the Wi-Fi connection to watch episodes of Heroes streamed from Netflix--the Roku periodically had to pause and adjust video quality to accommodate reduced bandwidth, and when it did, the image would noticeably deteriorate, displaying artifacts and pixilation.
Such issues pretty much went away when I used a HomePlug AV powerline ethernet adapter for my network connection, and while the lower-resolution image quality wasn't as good as with the high-def model, it was certainly watchable. You do have to settle for plain stereo audio, as opposed to the 5.1 digital audio available on high-def Roku models.
The Roku SD looks like the other Roku models--a small black box about the size of a frozen-food lunch--but with a lot fewer ports; it has just those required for a composite video/stereo audio hookup, ethernet connection, and AC adapter. The device comes with a composite video cable and an AC adapter, but you're on your own for the ethernet cable.
The Roku SD has the same simple and intuitive interface as its pricier cousins--and the same simple remote for controlling it. The remote, only a few inches tall, has a Home button on top, four arrow-wheel keys around a select button for navigation, and, for controlling video playback, a pause/play button flanked by fast-forward and rewind buttons.
Pressing the Home button brings up the main menu, which shows icons for settings, the services you can access through the Roku, and the new, free Roku Channel Store, where you can add services to (or remove them from) the main menu. You must set up a free account with Roku to use this feature, though--without it, you can only access content on Netflix, Amazon, and MLB.TV (Major League Baseball's premium service), since they're the only services preloaded on the main menu. (On new units, Roku says, you'll have to create a Roku account during setup to access any services, including the ones preloaded on older boxes.)