3D SHEETS ...WHATS THE POINT?

What is the purpose of 3d sheets? 

How should they be used?

You can rotate your 3d model  inside the sheet

You can dimension them but those dimensions may not be correct unless the model is rotated flat to the display.

You should be able to rotate a referenced model any direction and get the correct dimensions.

You should be able to change the view setting per attached reference file. Hidden line illustration etc. with out having to save views 1st. 

ss-2 & ss-3