Join Date: Aug 2006
Location: Maple Ridge, BC, Canada.
Interest: That of the 2-stroke variety
As much as I like VBulletin, I run a site using the newest 5.xx version and it's not nearly as good as the older version. Sure it's stable, but in my opinion I would not upgrade to it until it's developed a bit further. It leaves alot to be desired from a design standpoint, and is probably just now getting past what should have been a beta test phase. They are working on it, and plan to continue to work on it, so it should be a good option soon enough.
PM me if you have any other questions about it, I'd be happy to go into greater detail.