I have it. It definitely does what it's supposed to do, and it's a great fit for my needs. It's not audiophile gear, though... no digital out on the receiving unit, among other things. I've been quite happy with the SQ, but my speakers and amp are not the best so I wouldn't go by that.
It uses Bluetooth as a transmission medium. It occasionally has minor troubles with my 2.4ghz wireless phone, but I seem to have ironed those out of late. I'm not sure whether it would conflict with a 2.4ghz Wifi network at all... a Bluetooth expert would probably have a better sense of that (this is my first Bluetooth device, and I don't have a wifi network).
Advantages over the APX:
-It has a remote (albeit not a great one) and controls on the receiver itself which work quite well.
-You can output any DRM/non-DRM music or sound to it, as it acts as a USB sound card.
-You can use whatever music app you like with it.
-It looks cool on your bookshelf.
Disadvantages:
-It doesn't really work great with Itunes, as Itunes doesn't allow you to select the output device for your sound inside the program (so you couldn't have Itunes split out to the receiver while you played something else on your computer speakers). It works much better with Winamp, WMP, or another Windows dedicated app like Musikcube (my choice).
-It only works with Win2000 or XP.
-The documentation is pretty crummy, although the device is very easy to set up. Many complaints I have seen about it online have resolutions, but they aren't clear in the documentation.
Unknown Quantities:
-I don't know how the SQ compares with other units. This is my first try at a wireless solution and I don't know anyone else with one.
