I also auditioned C1 sign in the dealer several months ago. It is the best little speaker I heard though it may be overpriced at about 60K. However, C1 sign needs a high power current amp to drive it.
The performance of C1 sign improves a lot when it matches with a high power current amp such as burmester 911. If it matches with Burmester 082, its performance is just 60% of 911 MkIII. So dyna speaker really demands very much!