I honestly didn't think about using orbital information to develop my own VV by combining vectors :S. I figured the game might output the VV and other navball markers in a similar way to the attitude, ie pitch, roll, heading. I guess my primary use would be in flying. Utilising the difference between the VV and attitude to calculate a crude angle of attack for things like best lift to drag ratio, 3 degree glide slope approaches, maintaining level flight a whole lot easier, etc