Having all these gizmos is all very well, but there is no real substitute for a good rule of thumb and a knowledge of the real (actual - not what they tell you) weight of the aircraft. I have very clear recollections of all sorts of unknowns being shoved into the forward hold at BOG and only coming to light because of my insistence. Bring back STAN of the VC9! At least you would then know the real weight.