My opinion is that the campers mentioned here reach their limit at light off-roading. The materials, components and designs may be reasonably good quality but they are basically the same approach used for decades. They work well for standard campgrounds and maintained forest roads, but things break when subjected to rough roads. Everything is prone to failure including the camper mounting, structure, appliances, storage, and water tightness. If you are a seasoned backcountry rat who is comfortable with frequent inspections and fixing stuff then they are usable, but frustration may set in after enough repairing, rebuilding and replacing. Goes with the territory? Part of the fun? Personal choice.
Of all the removable truck campers I have seen the only production unit that is specifically designed for off-road is the XPCamper. It is built from the truck frame up to fix the limitations inherent in conventional campers: a cushioned suspension system, true monocoque shell, slim profile, marine grade appliances and latches, and self-sufficient power and water systems. However, you had better be willing to wait a year or more to get one, and to pay a premium.