Voted: I hate them both I have heard bad things from both. But if I was forced to choose between those two I would probably go with IPB.
IPB: Has 6,800+free and mostly beautiful skins. Is pretty darn easy to use. Can be FREE. Usually loads pretty quicly with little down time. VBULLETIN: Costs $160. Has no pre-loadable skins. Is difficult to use. Is often slow to use with excessive down time. IPB rules.
It isn't. AFAIK, the free version 1.3 has been discontinued. But yes, free hosted solutions are still available. (but they give very little control) There are over 1000+ free vBulletin skins available at vbulletin.org Downtime has nothing to do with a Forum script. If it's a web host that's slow in serving / processing pages, then no script can help. vBulletin can get resource heavy if you load it with every other modification available at vb-org; which you or your forum users won't even use at all. Just my $0.02
I've been on and staff at many forums of both software. vBulletin has better moderator controls, thread tagging (even though I don't think it was added with much thought), more support for integration with other software, and a hook system for plug ins already. But... I don't get why they added the whole social group thing. The admin control panel is a mess. Invision Power Board on the other hand has something a little similar to the hook system, but IPB3 will have a fully supported one. Even though the modding community is smaller, they have all the mods that are wanted enough. IPB also has a nicely layered ACP and I hear skinning is easier. Overall I think IPB is more flexible or at least when IPB3 comes out. They made a lot of announcements about how you have more control (BBcode, profile fields, removing stuff like the calender, etc.).
I made a free IPB 3 days ago. The address is www.z4.invisionfree.com/LaurenLeeSmith So, yes it can be free.
Care to explain why? I explained why and I hoped you read it. vB and IPB are just as powerful, it just depends on the person running the forum. o.o; Indeed.
I'll take an old version o IPB over a hole in the pocket any day. Another thing I like about IPB, is that add-ons and plug ins from other boards are compatible with it.
As a user I love vB, and find IPB annoying...then again, I find the new vB profiles equally annoying. As an admin, I have yet to try IPB other then as a test run for a week or so, in which time I could hardly find anything, as it was very confusing, where as with vB I read the manual and was going in hours.
What? All you do with IPB is make the categories and forums, set the permissions and you're set. Tis simple.
IPB and vBulletin are fairly similar in terms of features, security, and advantages. It's kind of silly to compare them. Although, one vBulletin forum I used on a silly website got easily hacked once it wasn't updated for a little bit (my fault). But my IPB never got hacked even when I forgot to update it.