I have a box truck and I have been really surprised at how bad the gas mileage is. Mine is a 96 ford E350 with a 14' box and my mileage is in the 7-8 MPG range. The box is nice and convenient to see everything spread out in front of you and there is tons of room but climbing in and out takes its toll. Also getting the shelving and tool hangers set up is costly and takes some time and no matter how much time you spend planning it two weeks later you are ready for a redesign. The only thing that it is better for is transporting plants. Plus everyone wants to borrow it to move with. My vote is for the Utility bed.
“If I accept you as you are, I will make you worse; however, if I treat you as though you are what you are capable of becoming, I help you become that.”