Another advantage to flat towing, is no additional weight put on the Truck/camper. Simply stated, no tongue weight. Because there is no tongue weight, no special heavy duty hitch requirements. Towing a trailer, you can easily spend $1200 to $1500 on a hitch only. Then maybe add a Weight Distribution Hitch. Not often I see big Class As towing a trailer, but frequently see them flat towing. Must be a reason.
Brake requirements on the vehicle being towed, vary from state to state, and I think required in Canada. I am sure someone will argue this point, but many confuse trailer brake requirements with towed vehicle requirements. Brakes systems for towed vehicles typically cost between $500 and $1500. The various sites with Towed vehicle brake requirements are full of errors, they sell brakes systems, check with the individual state.
Wayne