My personal choice, if I could have only one spreader, and was going to have it on a truck that already had a dump body, would be undertailgate. As it is I have both, undergate on a dump truck and vee box in a 3/4 ton pickup. Due to the better maneuverability of the pickup I can ususally spread faster, but I have to make several trips to the stockpile. With the dumptruck I can haul 5 tons per load and only have to load up about once every other run. There is no plow on the big truck (yet, still) so using it requires a second trip over the route. Used to have the spreader on an F-350 dump, hydraulics were from a clutch pump, worked fine other than capacity was reduced to what the truck was comfortable with, about 3 tons max.