VB is a very capable BBS. I help run a site and our forum uses it with about 1300 members. Of course, this is not nearly the same scale as HWC but I have seen several forums that use it with memberships as large or larger than here.
One thing we found really cool is that we previously used UltraBoard and the VB developers provided a script for us to convert all of our users and posts over to the VB format. This was immensely helpful.
Friends don't let friends buy P4s.