We used jFusion to integrate our phpBB users within the Joomla authentication system. We were already using the mehdi bridge, but the way it wanted to integrate the users was not fitting to us, because mehdi requires that all users must create a new password after integration.
So, I thought, let's give jFusion a try. It was a wise decision! JFusion's integration is amazing! You just have to follow instructions in the documentation (although a bit outdated), understand the difference between master and slave plugins, and you're set! Just be sure you know what you're doing.
Now we have Joomla as a layer where the mehdi bridge lays the phpBB display, and JFusion handles user-authentication. Great! As a token of gratitude we have donated to help jFusion's further development. It is a great product and a lot of hard work has been put into it. Thank you again jFusion!