Ideally your DIN should be in the middle of your binding's range. Yes, they're designed to work properly at all the DIN settings, but having the springs away from either extremes will help it stay alive longer.
Also, the materials on a binding should be designed for the DIN range on it. So generally speaking, a binding with a DIN range of 6-14 should be a lot more durable than a binding with a DIN range of 2-9