If I change the weights in the back of my 915D2 (4g, 7g, 9g, 11g, 14g), what kind of effects am I going to see in the ball flight, weight, etc.? 
It comes with the Red (9g).  If I add a lighter weight ... it in theory would hit the ball lower?  If I add a heavier weight (14g), it would hit the ball higher?  The more weight moved to the rear, adds overall height.  Correct?
I know that head & shaft combinations go through tolerances and extensive testing to match the correct weight/shaft combination to make sure they are perfect.  But I'm a tinker kind of guy and like to play around with different shafts until I find the right one.  Unfortunately, we all don't have a Titleist Tour Van to follow us around from place to place.  LOL 
My current combination is Rogue Black Stiff, Red weight, set to D3.  Am I going to see a substantial difference in ball flight one way or the other? 
Thanks for any input.