they are very nice indeed!
The perpetual calendar mechanism is very elegant and stealthy on the dial. But finding one in the real world is tough because they are having trouble training and keeping watchmakers who can assemble these finickity movements.
The tolerances are small and once assembled, are a pain to change anything later. The original inventor of the movement tries to help out but really, Moser are on their own. They need to reduce the variations offered so that the few watchmakers can streamline the production and speed up.....
Regards,
MTF