I just noticed that the default setting for private messages is to save a copy and send read receipt. Being a veteran of several VBB sites, I have found that not enabling those options greatly eases the server side storage issues, as well as making it easier to the users, who often don't know their box is full because of the copies.

Also, for the interests of band, the default view option should be at least 20 to 30 posts per page (rather than the default 7 on terb). Doing so will save you $$ on band - since the client doesn't have to download the page template as often in long threads.