We use all touchscreen KDS units at one of our busiest locations and don't have many wear & tear problems. During busy lunches they can average up to 9 orders coming into the kitchen per minute. They wrap the screens with saran wrap at the messier stations, (fry especially), but try not to cover the vents too much.
You just have to drill it into the heads of the line cooks that they can only bump orders with they're fingers, not spoons, tongs, etc...