I ran phpbb for months on two of my sites. Once the sites grew It became evident that phpBB was outgrown. Outgrown, what I mean by outgrown is that it lacked the features people where used to on other major forums. Usercp, ajax (edit, reply, and post) and overall it felt like it was lacking. I was originally going to wait for phpBB3, but it has been annouced two years ago and still is not officially out! Get VB and don't look back, I didn't!