I use them both because I don't have the money to pay for two licences but I feel that vbulletin is way better. But that could be just because I'm so used to using vB that it is hard to use any other board. . Also with vB3 IPB was probably blown out of the water.
Today at 01:54 AM Spitfireisgod said this in Post #3 Smoothie, you cant ask a question like that here, 90% will say vBulletin, if you asked it at IPB forums, 90% would say IPB.
you gotta ask at a non-biasis for a legit anwser
I've been playing around a bit with IPB, seems quite nice.