I have only experience with older varsions of phpBB. I think

1. The code is good enough. Version 3.0 and above should be even better.
2. There are a lot of modifications.
3. There is a large online community supporting the software.
4. It is regularily updated to meet newer requirements.
5. This http://starfoxtj.phpbbhelp.org//phpBB/toolkit/ exellent tool is one reason why you should choose phpBB. One modification. I don't know how compatible it is with newer versions, but since it is relatively easy to understand the code, it should be.
   
   
   

__________________
Mini Network:: Financial information at your fingertips
Learn object oriented programming where it started