Thanks Lee. I noted the dimensions from this previous post.
For my taste personally, aesthetically the room is a success. I haven't heard it so couldn't comment in that regard.
Construction wise, I believe that they have built this room within a manufacturing facility, so presumably a false suspended ceiling. And presumably timber stud walls for the original walls prior to the additional acoustic space created within that. This immediately makes the problems and therefore complexity to control those that much greater. But you can see the construction and acoustic principles they have implemented by studying the film. All room designs are somewhat complex, but its certainly an elegant example.