From my sight, phpBB has not the most features. There are other bulletin boards with much more features, which looks very pretty and shiny. For example vB has some kind of social network and CMS inside. myBB has reputation system, calendar and events etc.
Why am I stuck with phpBB for years then?
Answer is very simple. phpBB is really the best bulletin board solution on market and here are my reasons:
1. phpBB is really secure, there is no known vulnerability and we dont know about ANY phpBB board which has been hacked because of security hole.
2. phpBB has the best support forum and supporters. They can help you with everything
3. Lack of features is solved by many really good MODs. There is a good reputation system, CMS, Blogs, Calendar, Social network. You can add pretty much everything to your phpBB
4. phpBB has the best, lightweight and simple to understand code. It is fun to customize it, not like ugly vB or myBB code..
5. phpBB has the best permissions system which is important for every succesfull forum site
6. With phpBB you can be sure that there will always be live support and new versions. I am pretty sure phpBB will not die like other bulletin board softwares.. You can look forward to phpBB 3.1, 3.2 and 4
These are only few reasons which comes to my mind at this late hour (1am) but I am pretty sure it is enough for you to decide what is better for you.