As I use WP-Types more and more, I find a true elegance in the user interface. I've been able to do some pretty sophisticated type and field management intuitively without having to search for guidance.
Have you considered writing a case study about the development of the plugin? I believe it is the best in its class, and I've tried quite a few, and I think there are many folks who would be very interested.
Also, at least for me, it has been easier to understand than Drupal's CCK/Blocks/Views.