One of the few things I like about AutoCAD compared to Revit is that you can snap lines between different XYZ coordinates. In Revit, you can't just draw a line in a 3D view and get it to snap between any two points -- you'll probably have to define a workplane for the line to be drawn on first.
Ugly!
I would love a "Free" Model line tool which has no defined workplane and snaps between any two endpoints regardless of their XYZ location.
On the monster twisting tower project I'm helping out on (first it was Calatrava, now everyone's doing it ), one member of the team wanted to layout a line-based framework for the mullions. Do it in Revit? Not a chance -- had to be done in AutoCAD.
All in favour: vote away!