We have moved away from vBulletin to Xenforo last week. After a week of many hours of work, lots of coffee and hardly any sleep it's time to dump the site link here in the XF community forums:
www.racedepartment.com (wordpress integrated with xenforo)
We are a motorsport and sim racing community hanging around the web since December 2006. "Sim What?" I can hear you think. Yeah ehm this for example
Started like many boards on a free PHPBB forum and moved to vBulletin after a few months. During the heydays of vBulletin 3 we were extremely happy how the board performed. But ever since we have moved to vB4 in December 2009 and purchased the full suite the problems got more worse with every software upgrade eventually resulting in pages hardly loading anymore (up to a minute or more).
Now we have imported almost a million posts and over 100,000 members we can only say that things have REALLY speed up. Pages load in a second and the social features of XenForo are second to none. Loving it so far.
Will update this post once we have completely finalized the site and forums.