One feature that is lost from the old forums is the ability to view new posts only in threads that you've posted in. I used to use that as a filter sometimes when I didn't want to read as many posts on a given day.
Go into your user options and setup a no-email subscription on threads you post in.
It's not just switching from SMF -> vB, it's the fact that the brass wants the forum DB to be in synch with the Curse auth DB.
So we (read: I) had to not only hassle with the login plugin (which we now think actually works more or less properly XD) but a Curse Auth -> vB user import script XD