Are you sure? None of the releases that were put out in that format had labels on them. The best way to know is to put in in Windows Media Player or some other player that can recognize HDCD and it will tell you. AVCD-17239 is the serial number.
If I had any criticism I would say that RAINBOW is a bit on the loud side. I would love for the dynamic range to be improved and I am always in favor of crisp detailed sound.
I keep holding off on buying Ayu stuff because I am waiting to see if anything is going to be re-released this year or next year.