It's a pretty neat system. I have not seen it in person, but I did consider getting one since Zaxcom just released their built-in Soundfield decoder for the Deva. However, after some conversations with engineers using Soundfields, the recommendation was not to get one. The biggest issue seems to be getting consistent results from the soundfield mics. One time you'll get stellar results, the next mediocre results when the setup is identical. For me to justify $6K for a mic, I want consistent results (and more paying audio jobs!)...
Wayne