However, there are two VERY important aspects to point out that is forgotten here:
1. Using Joomla as (master) database for your users, leaves you with little or no user management. As you probably know a new Joomla user does not need to be confirmed by Admin before entering the site, nor has Joomla any built in security features like 'captcha' or checking for password strength.
That is ALL 'normal' Joomla features... ;-)
BUT, if you install phpBB Bulletin board AND JFusion, setting the phpBB as Master database, you get all this working in Joomla! i.e All phpBB user admin features are now used to register/maintain users!
Ok, maybe you want 'captcha' in the Joomla! contact form, then you need to install a separate 'captcha' for that.
But other than that, this extra goodies solved my problems when installing this combination. And who doesn't install a forum on their professional site?
I'm using Fireboard in production today, but not for long I can tell you.