Streaming media from a hard drive is pretty much flawless. The machine doesn't come with a drive by default, but fitting one is easy and high-capacity drives are far from expensive these days. During our tests, media played without stuttering right up to 1080p QuickTime material. We used a variety of material to test this including MPEG-4 video in both Matroska and QuickTime wrappers. The A-100 didn't have a problem with anything we threw at it.
Over the network, we were able to get 1080p video working without a hitch most of the time. There were occasions where playback stuttered, but this might have been a problem with our network or even the file we were playing. The Children of Men trailer stuttered, but the Get Smart clip played flawlessly. Happily, 720p video always worked flawlessly and for the time being, 1080p isn't practical to download with a movie weighing in at 14GB and virtually no TV stations broadcasting in that format.
USB playback was flawless, but only with a fast memory card. Using an older, slower stick meant we got some juddering at times. This isn't the A-100's fault, so if you're planning on playing HD material over USB, make sure it's fast.
You also get access to some Web services with the A-100, but this is the buggiest part of the system. We used the Flickr photo stream and the box hung on us. Other services like Yahoo! Weather were fine, though.
The Popcorn Hour A-100 is a really impressive piece of hardware. It's exceptionally well priced, although you'll have to pay to import it. Even so, it could cost you a little less than Apple TV. Also, Popcorn Hour has continually produced firmware updates that add new functionality to the device. The active user forum on its site has areas where users can suggest features and this feedback is monitored carefully by the company.
The only other product we've reviewed that comes close to the A-100 is the D-Link DivX Connected box, but that device has very limited codec support. Apple TV has the built-in hard drive, easy synchronisation through iTunes, but doesn't support any useful codecs at all.
Edited by Shannon Doubleday