Let me just say that xenForo is without doubt the best forum software I have ever used. It is admin friendly, very easy (but powerful) to customize, extremely user friendly and nice looking (the members of my forum are thrilled!), and not to mention the community. I see great things in the future for xenForo.
I went from vBulletin 4 to this, and in retrospect, I can't believe I wasted money on vBulletin. I mean, this is a beta software and still it outclasses vBulletin, phpbb and the others I have tested. Of course, some features are yet to be implemented, but in terms of usability and a stable platform, it's absolutely perfect.
Cheers from Sweden!
PS. No, I am not getting paid to say this. I just thought I'd take the time to give my kudos to the devs and the community. So to all of you who still haven't decided if xenForo is worth it - it is, believe me.