We've been using it since the first release candidate over at
http://www.project1726.org/forums3. It works better than any other board I could find! Installing mods is a simple process (not automatic, but not difficult work either) and updating versions is as simple as it could get (mods usually work after updating, and if not, the author usually updates the mod to work with the current version). I've been waiting for some time for a decent calendar and/or gallery to come out (several in development and pre-release stages), which should increase productivity ten-fold.
Overall it's a very nice community forums package that everyone should use!