Unfortunately the php form architecture is free, so it would be hard to compete. And, in my opinion, it makes for a better forum, with the ability to quote, revise and edit posts, attach files and generally be more creative. Joomla is also a good forum architecture.
The appeal of the Mudcat system, I suppose, is it's quaintness - it's hopelessly out of date and non-user-friendly, but it's what we're used to!