The forum is nice and easy to set up. The problems come when trying to couple the bbPress (and/or BuddyPress) plugin with a membership plugin. As I have tried to do TWICE.
After research it seems that bbpress (and/or BuddyPress) do NOT play well with 'membership' or 's2 member'. I'm not sure whose responsible for the issues, but personally I think they should all get together and resolve the problems. Otherwise, having a membership site with a forum is extremely problematic because the administrators loose their access and instead of doing to the dashboard or being able to login in the first place, you are met with this message: "You do not have sufficient permission to access this page".