I'm not sure they are imported into the USA at this time.
I had the opportunity to try a set under our line-stage at the last Rock Mountain Audio Fest held at the original location. I'm not a major tweak-er but I do believe everything can matter. I thought they improved our system's SQ enough to keep them in the system for the duration of the show. I tried to buy them from the guy who brought them to our room to use. He said they were prototypes and not for sale.
Mike