I have to keep my computer downstairs and so therefore the 10 metre cord they gave me was a waste of space.
The adaptor is excellent though.
Never had any troubles with it. The connection quality is fantastic, download time is just as good as being plugged into your router.
When i first got it though it didn't connect instantly if the same happens to you on your xbox dashboard. Go to system and select network settings then select wireless connectivity and you'll no how to do the rest.
Is a bit on the expensive side but trust me it's worth it.