I run a topper that is taller than cab height to accommodate a large kennel on top of the truck vault. The only time I feel at a disadvantage is when loading a bull elk into the bed. you have to put the head in last and leave the topper door open, which I’m not a fan of. if you are building your own, which I have done, I would really think about how much height you will need inside the drawers. I store guns, optics, ammo and fishing gear depending on the season. The truck vault system really does drastically increase the storage space in the bed while also keeping the bed completely open. If you put the numbers together of what good materials cost to build a drawer system similar to the truck vault, you’re not money ahead to diy if your time has much value.