Some choice quotes:
we’ve reduced the time it takes to publish a new article from almost 15 minutes to a few seconds by moving from Movable Type to WordPress
I’ve found again and again that WP is not only up to the task of serving as far more than a blogging platform, it’s a great content management system for many types of sites, once you learn a few tricks
In the case of CDT, publishing times were a nightmare with Movable Type. Search performance was horrible, and the comment spam problem caused such a drag on the server that we’d had to disable commenting altogether. Now, with the site fully tag-enabled, searchable and comment-able, loads are down dramatically and publishing times have dropped dramatically.