vBulletin is the most used forum platform. The installation process requires more steps and is a little more complicated than phpBB and myBB installations for example. But this script includes a detailed manual and you can handle it with easy if you are patient and read the few steps involved.
vBulletin has a huge amount of options, probably will cover all needs. Even it looks overwhelming at the beginning, the admin panel is very well structured in sections and in time you will get used with all menus and options. Probably you will need to Google it when you search an option or use the included search function to find what you are looking for.
This platform has the most complete set of features and this is good, because you never know when you need one. And they are installed from the first time, so you don't need to install and maintain plugins. This is an advantage, all functionalities are included and you will not risk to have a plugin unmaintained by the developer and exposed to potential security risk.
Your users need also to have a lot of features and options to write threads and to respond to them, to make and edit a profile or to make new contacts through the forum.
vBulletin is one of the most popular platforms and many people are trying to abuse the script. Fortunately, they release new updates and security patches so you can focus on talking with users instead deleting spam from the forum. Is important to keep vBulletin, like any other CMS, updated. You can follow them on Twitter or subscribe to RSS feeds, to be informed about latest updates.
The features offered by this CMS are more than those presented in our comparison. They have hundreds of features and options, including the option to make a blogs, polls and more.
There is a large community that offers how tos and tutorials, also the developer includes a comprehensive manual and a support forum.
You spend some money because is a paid license, but you will get a huge amount of features and you will be sure that the forum is secure because they have a large team which release updates and maintain and improve the source code.
They have a cloud package so you will not deal with updates or server management and you will pay a monthly but smaller fee.