Image format support that's limited to just JPEG is also quite poor. In this day and age we'd expect at least GIF support and preferably TIFF and PNG as well. At least audio format support is a little more impressive, though there's an obvious lack of any lossless formats in the list.
It's not just the format support that is disappointing. Seagate has also implemented an underwhelming interface. It uses a simple system whereby along the top is an arrangement of four tabs; 'music', 'video', 'photos', and 'all', and by selecting a tab you correspondingly filter the contents of the screen below. While it looks perfectly nice, with its clean layout, it lacks some basic features.
For a start, there's no music library interface that scans your music files and organises them based on their tags. Instead, all navigation is done by just browsing back and forth through folders. Then there's the 'all' tab. When selected it doesn't actually show all the files in that folder; just those that it can play, which can lead to some confusion as to whether you actually copied the files to the right location in the first place. Also, while we liked the idea of the preview pane for videos and photos, we found it somewhat frustrating to wait for the preview to load (which could take several seconds) before we could tell the player to start full-screen playback - if I know it's the right file I want to be able to play it immediately!
Finally we come to the price and here the Seagate FreeAgent Theater can at least claim parity with the competition; both the Theater and Western Digital WD TV are available for around £80.
Seagate's FreeAgent Theater is in isolation a reasonable device. It is easy to set up and use and delivers a good quality viewing experience for a reasonable price. However, take into account the Western Digital WD TV and things look less rosy. The latter has better video, audio, and image format support, an HDMI-out, and a better interface. So, quite simply, the only reason we'd suggest the Theater over the WD TV is if your TV doesn't have HDMI.