In looking back on this code I wrote over two years ago, I think it's pretty normal to second-guess myself and think of better ways I could have written it. While I may have written some of the implementation code differently, I think I'd still design the overall solution the same way. This code has stood the test of time, as the client has since added new distributors and new request types all on its own, with minimal help from outside service providers like me.
Currently, as director of a bioinformatics department, I have used this code to demonstrate several things to my staff as I teach them object-oriented design principles and XML parsing techniques. I could have written about code I have developed more recently, but I think this demonstrates several basic principles that are important for any young software developer to understand.