I went ahead and ordered one - it arrived over the weekend.
From the pics on the Outlaw website, the unit looked like it was 4" to 6" square in size. However, this thing is really tiny!
It paired quickly to my iPhone and seems to work well with no set up issues. The BTR-100 was connected to my pre-amp using the mini-stereo to RCA cable included, and was paired to an iPhone using a regular Bluetooth connection (did not use the NFC feature, and I have no idea what communication/compression algorithms were in play). I have not done any critical listening (nor do I plan to), but I did a quick "one song" A/B test on my main system to get a feel for the sound quality. My initial impression is that the sound is on par with a basic CD player running through a basic A/V receiver. That is, the sound is clear with low noise and reasonable detail, but lacks that warm and airy sound that we all strive for in our systems. Or, in other words, pretty much what you would expect. This will serve my needs well of providing guest a way to play music w/o a learning curve or software installs.