I've used it. I love it. vBulletin is WAY too bloated dude.

I already have the skin picked out:
http://www.bluepearl-skins.com/xenfo...le?style_id=17

Skinning is SOOO much easier in Xen Foro, and so are mods.

I been messing with a demo and admincp
http://demo.xenforo.com/110/index.php