bprepn,

Not to contradict you my friend but my above example is right on the money for a majority of the bows out there. There is a larger speed increase for the increase in draw weight in comparison to the decrease in speed for the increase in arrow weight.

I would be more than happy to do this comparison on any bow out there.

To put it very simply, a 70 lb peak draw weight bow shooting at 5 grains per pound of draw weight will shoot several feet per second faster than a 60 lb peak draw weight bow shooting at 5 grains per pound of draw weight. One effect does not equally cancel out the effect of the other. Equations on paper are fine but practical experience tells me otherwise.