Congratulations. I also read your article about document control, and immediately liked your approach. For example, restricting folders to just one level and not folders-within-folders, seems to have helped you in eliminating gratuitous complexity.
Side question out of sheer curiosity: Do you have AutoLISP/ObjectARX plugins that interact with your site?
We don't have such plugins yet, but our system is built with the eventual release of an API in mind (so that any number of clients could connect, not just the Flex client)... if you want to build something that interacts with it, just contact me and I'll see how we can help you.
Side question out of sheer curiosity: Do you have AutoLISP/ObjectARX plugins that interact with your site?