tanneralis: What's the point of hitting the ding if the ball takes off 10-15 feet right or left of where you aimed it......you may have not aimed spot on for a crosswind or whatever but the ball should at least start where you aimed it
No it doesn't. AFAIK, ball flight is only an approximation, while the point of halt is fixed from the beginning.
Once we stop the meter, the whole shot is calculated in a split millisecond before the ball starts to move. From then on, the outcome is fixed and the visuals are secondary. So, it may happen that the ball starts further off than we expect, forestalling the physical movement (not excluding that there might be an error in these calcs). Still, the outcome looks o.k. in most cases.
tanneralis: During the same round i hit a 150 yard club 100% with full backspin [snip]
I can't really explain this but I know that full bs may importantly shorten the shots - see your 138.
For the other outcome, I call VEM *waving the magic wand*.