I am satisfied with the space that the box offers. The quality and design of the box are premium. Anything built for the healthcare industry is top of the line. It's all aluminum and super strong. The box is already outfitted with insulation, lighting, inverter, ac, cabinets, 120 connection, and exterior compartments. Those are just a few things that I can list. That's less work and expense to have those things. This box was on a f550 and it drove poorly. The new setup is only two feet longer than the old one. The f700 frame rails were designed to take the exact length of this box. Just because you can extend the rails and place something larger doesn't mean its beneficial to do so. I rather have a quality box with reasonable room. This way I'm not excessive on weight and there is less stress on the truck. Less is more