I’m trying to adapt to the new tabbed interface in Office 2007. So far, all those pretty buttons seem like a hindrance. Vensim, on the other hand, is a bit too austere. I’ve just installed version 5.9 (check it out, and while you’re at it see the new Ventana site); my setup follows. Note that this only applies to advanced versions of Vensim.
First, I allow the equation editor to “accept enter” – I like to be able to add line breaks to equations (and hate accidentally dismissing the editor with an <enter>). You can do this anyway with <ctl><enter>, but I prefer it this way.