Weather we admit it or not, we all gap shoot to some degree. For hunting ranges inside 40yds a heavy arrow will have a smaller gap in your sight picture.
Try this: shoot an approx. 9gpp arrow, draw and point it, the tip that is "point on" at a 20yd spot.
Then try the same with your heavy one. See how much closer you are!!
Those heavy shafts setups give approximately 35yd point on, depending on draw length, gives the sense of point and shoot! They are quite forgiving of form mishaps as well as a bit quieter out of the bow. I like how they don't get pushed around quite as much by un-forseen twigs in your shooting lane.
As long as they are tuned to the bow they will help you quite a bit.