Somebody once pointed out to me the following interesting fact. Take a HIscox guitar case and see how far you can throw it. Then take any hi density foam case and perform the same act. You should discover that the weight of the Hiscox case allows you a greater distance due to its great weight. Oddly, the hi density foam case resists long throws.
Now…imagine you are a baggage handler in a really bad mood. You get a guitar case and, just to relieve the tension, you hurl it at the conveyor belt or into the cargo container. Result is that the foam case protects the guitar more because its difficult to achive a velocity with one that will result in the contents being damaged. Go figure.