The down sides to heavy arrows is the trajectory but if you know your ranges you should not have a problem now that we have hand held range finders. Also heavy arrows will make your shots more accurate and with a quite bow you will get better shot placements on your game animal.
Per the ranch fairy pig hunts animals still move while arrow is in flight.
And Ive had fine accuracy w faster/ lighter arrows.
Heavies have advantages and disadvantages.
Up to the shooter to decide what characteristics he values most.
