I thought I would post a review on here so that people don't get confused by other reviews.
A few people here seem to think this wireless adapter is in someway faster than the official XBOX one, and basically its not. This is a 802.11B/G adapter, and the Microsoft one is 802.11A/B/G which means it's just as fast but also has support for 802.11A. 802.11A is the same speed as G, but doesn't suffer any where near as much interference as G, and is the recommended frequency for streaming music and video.
There is a reason it's cheaper and that's because it has less features, more difficult to configure, and cheaper technology. For the difference in price it's really not worth the saving compared to the official one.
Saying all that, if you don't mind the extra setup time, aren't gonna stream video, and want the extra tenner in your pocket, then it's not a bad alternative. I just wanted to make sure peoples decisions are based on fact and not misunderstandings.