Besides the extension works like a dream, I would highlight the extremely fast and friendly support.
The documentation is growing together with the project, and the team seems to be very talented and experienced also in general joomla things. I got several other useful information regarding issues outside JFusion just searching and reading their support forum.
For those who use joomla 1.5 with phpBB3 this is The Bridge. Highly recommended.
It works right out of the box, no hacking, no tricks, no surprises, it just does what it promises. It also has very good default presets in the configuration options. That means you can, but not necessarily need to go through the settings.
With Kickstart it simply couldn't be easier to use even for noobs.
I'm just so sorry not to find this component earlier. It would have saved hours (days) of boring and dangerous work for me.
Congratulation and big THANK YOU for its developers. This component should be part of the core joomla framework.