Mine came with it from the factory. It's 3 years old now and had held up well to the dents that I've put in the bed and wheel wells from firewood. However I decided not to get it through the factory when I just placed my order for a new truck. I didn't like how thin it was applied and feel the aftermarket ones are thicker and may resist denting more. On the bed near the rear window you could see the white paint from my bed through it.
I was told it was part of the bumper to bumper warranty which means it's only good for three years. The after market one that I've arranged to be installed will have a lifetime warranty. Only time will tell but the price was $75 more for the aftermarket so hopefully it'll be worth it.