vBulletin has many more features than phpBB, looks much more professional and is much more user friendly from a User's / Moderator's point of view. The styles are also much nicer for vBulletin than phpBB and the MODs are more effective.
Only disadvantage is the fact you have to pay. Mind you - it's worth it. ~wink~
I your going to get a vBulletin the best for you is to be a member of www.vBulletin.org. Also it has been said that installing Mods to a vBulletin is way easier then to a phpBB.
They use an upload system similar to SMF, where you download the MOD and it contains and xml file. You upload the full zipped MOD and it installs by itself, using the xml file. Its nice if it's a big MOD and you don't have 4 hours to manually install it.
If there were a conversion i could do, move my forum to vB, i would defenitely make the move. i've got the money, i just can't bail out on what my members and staff, as well as i , have worked so hard on over the last 6 months.
The ProBoards one didnt come with the download, unless its named something different. I disagree with what alot of people on here are saying, I wouldnt switch to vB if I could. I plan to stick with phpBB3 until I have the money to switch to IPB, which I like better than vB.