Interestingly enough, I've examined the vbulletin software, and used/toyed with it a bit.
It's a good BB; seemingly well written and not too hard to customize if you know enough PHP.
It works off MySQL, which is another definate plus. One problem is if you only have access to one MySQL database but unlimited tables (as many people do), VBB does set up quite a few tables which could cause a problem if you've already set up your own tables.
As far as buying it...ehh...I don't think I'd personally shell out my cash for it. There are so many alternatives, make sure to at least examine them and see if there's not one you like better.
VBB is like a UBB for PHP (acronym, anyone?).
But if your time is more valuable than the money spent on registering VBB, go with VBB. It does have good spamming protection and customizability, even through a non-programming "admin" interface.
As for threading, that does cause arguements doesn't it?
I'd agree with him point, 馃槈
If someone simply asks a question and wants an answer, this is the way to go.
Now if the message was more like:
"I've been considering upgrading my pages to XML compatability, if not totally going the XML route, and maybe adding WAP integration.
What do you guys think? Is handling XML with PHP a good idea?"
To which I'd diminish into a tyrade about companys that went to market with WAP phones the second they could, without revising their technical manuals or even examing the state of WML as a whole, should be drug out into the middle of the street and visciously beaten with the sharp edge of a mouse.
To which someone would reply that WAP is great, and someone would say PHP is perfect for XML, and then someone would say how it doesn't validate XML blah blah.
It would be quite annoying to click on different topics over and over again, not knowing which reply came first without examing the dates, especially if your conversation was 80 replys long.
There is one big problem with sticking them all together though. The individual reply format is far more forgiving to slow connections. Once you've read a reply, you don't need to load it again.
But in the one page version, you need to reload all the previous replys. Even in a thread of only 40 replys per page, if those replys are to a big discussion, your loading time is going to be horrid.
(I once, in only 4 messages, filled over 20 pages of content into a single thread page- all rant. even with DSL the load time was attrocious)
So there you go.
Caveat Emptoure...which I'm sure is spelled wrong, but you get the idea.