Subforums are in both version and work perfectly.
The code in vB is laid out alot better than PHPBB trust me.
Its just a matter of finding a line, then doing as your told, like add so and so code after it.
Areas that are cluttered with posts/threads etc, can easily be moved via a drop down box when viewing the thread. Areas can be added easily aswell and have many options available when creating them.
vB3 even has password protected forums
Permissions is definetly in vB.
vB would cope better than any other BB board with a huge community