I read a few reviews on here and looked at a few other sites and could find no mention of Mac compatability. For £17 I thought I'd take a punt and I'm not disappointed. Sound quality is very good across the range and is comparable with FM radio transmissions. Range is about 20m without it breaking up.
This works just fine on my Macbook Pro (OSX 10.6.1 / 3.06Ghz C2D / 4Gb Ram). It doesnt auto select so you have to choose it as the selected audio output, easy to do (system/sound/USB SPIDIF) and it works perfectly.
Seriously can't fault this in any way. For this price I was expecting something ok but realistically I was expecting a bit of audio quality loss. The loss is so small that even on an 800w technics PA amp, it is barely noticeable.
A quality product and fantastic value. Highly recommended.