I love Xenforo, Discourse changes the way forums looked and worked. Xenforo is one of the industry leaders in premium forum software. They have an active community and gives frequent updates. Moreover it's a lot secure, simple to use, uses less resources. The only thing i like about Discourse is the monthly digest email. Most big online forums like Digitalpoint forums, Cpanel forums, Androidforums etc.. use Xenforo.
Both Xenforo and Discourse is new and stays in two categories, premium and open source. And Discourse is the best choice in open source software.
Anyway it's not about the software, it's about the people in the forum, i have seen many awkward looking forums with a ton of active users.
Good luck to HBB forum and great work @pradeepkumar