I'm trying to decide on what to do with my forum. I realize this may be a biased crowd since I'm posting on a xenForo forum, but... I'm currently on vB 3.8. www.powwows.com/gathering It's a pretty large vB install with 70k+ users. My first question is what large sites are running xenForo now in production? I've considered moving to vB 4x but I hear mixed reviews. Any experiences here with moving from 3,8 to 4? Our Pow Wow calendar is integrated into vB to pull user info. How difficult is it to do that same type of integration with xenForo? Thanks!