I won't go into too much detail about why I moved off of vBulletin. The short answer is vBulletin 4 was getting old. There was no immediate sunset announced but they a not going to support it forever, especially when vBulletin 5 has been out for years. After trying vBulletin 5 for five days it was clear it wasn't going to work long term. At that point I had to roll-back to vBulletin 4 and lose five days of posts. I had researched Xenforo before upgrading to vBulletin 5 so I decided to just rip the bandaid off and migrate. Apologies for the whiplash but we should be stable for a good while now. Xenforo is a newer forum app. It is much faster than vBulletin and it was written from scratch more recently so the code is not a spaghetti mess. Post any questions or issues you have in this thread.