We started out on wwwthreads in 2002. Switched to vbulletin in 2005 when InfoPop took over wwwthreads and then to IPB in 2010 because of the uncertain state of vbulletin.
We decided it was time to move on and it was unanimous that we move to XenForo. Other than me the staff never really liked IPB, but, at the time we wanted to move away from vbulletin there wasn't many options.
We have 52K+ threads, 292K+ posts and 61K+ members. There are another 200K+ posts archived from the now closed site submission status forums which don't show up in the totals.
The site is at http://www.resource-zone.com and forum is at http://www.resource-zone.com/forum