In the world of custom truck accessories, form often times overrules function, as we have to make sacrifices to look good. When we came across the new DiamondBack HD-X tonneau cover, we were skeptical of its long list of performance claims. Could a tonneau really keep the bed secure while also being load-bearing up to 1,600 pounds (that's two ATVs), open in the front and rear in a winged configuration, and add to that the .100-inch thick aluminum tread plate could be ordered coated in rugged Line-X for the ultimate in protection? Using our project Ford F-350 for towing, camping, and hauling, the idea of a tonneau cover never seemed practical, but with this new cover, it met all of our needs and we bit the bullet and placed our order. Arriving in a large box, the DiamondBack cover came in three panels and was ready to install with straightforward instructions. How did it work? Read along and find out.