Boxbodys are great. You don't have to worry about tents so as soon as you arrive in location you can have the kettle on even before you have finished camming up. All your equipment is more or less set up ready to get on with the job as if you hadn't even moved. REMFs just love them because they make living in the field so easy and comfortable.
Enemy box-bodied vehicles are beloved by members of The Intelligence Corps as they are invariably a tell-tale sign of something important. They usually vary slightly from one another which allows the discerning spotter to distinguish between a mobile bath unit and the Army level HQ comms wagon.