This is really one favorite feature. Plot the model drawing of a plan to DWF and other disciplines or users can use it as underlay adjusting the contrast and fade it as they want to. The DWF is smaller in file size than the DWG and that speed things up within AutoCAD compared to attaching a DWG.
The ability to commit to paper but also read back into AutoCAD is an advantage of DWF. An image format could be printed and also inserted into AutoCAD; however, using a DWF allows the AutoCAD user to snap to the geometry. With an image file, that just won't happen. So the ability to print, and also reuse, demonstrates how DWF goes beyond the paper.