I've got mixed feelings about this. It's very well implemented, it works perfectly it's configurable and it's easy to install and to use. Having said that it's not something I would use... not because I don't like it but because I don't have the need for it. I guess it's down to how people usually use forums, I always start everything from the main page and very rarely go down the category level. I saw Carlos' reaction and I can understand that for people who like to access some parts of the forums directly this must be a great tool.
Am I missing the point? I'll keep it installed on my machine for a week or so and I'll force myself to use it. It took me some time before I was addicted to Tomboy Notes and maybe I just need to change my habits towards this.. let's see.