A friend of mine has had two Util bodies on two different trucks. Both wore out the truck that they were mounted on, and he is hard on equipment. One saw many Baja trips on the rear of a 70's GM crew cab SRW 1 ton. That truck broke a lower ball joint from too much speed on the wash board road SW out of San Ignacio to the coast. That bed later took out an official double steel posted sign with not a lot of damage to the bed. Oops.......
No getting away from their weight, but I've no concerns about durability. I do dislike their departure angle and it would be a considerable effort to modify those that I've looked at to have a better departure angle.