Conclusion
The H3D 31 is a fine tool for making top-quality digital images. It is clear why it costs $24,995 – it's a low-volume product with expensive research and development behind it, and it is carefully made with expensive, excellent materials.
It is not intended to compete with Canon and Nikon. It's meant to be a different category, and it isn't nearly as convenient to use as those, even though it is as thoughtfully designed. Weight, speed, automation, and flexibility all took hits in service to support image quality.