If your husband wants a great towing truck that is quiet and has many great features, such as the exhaust brake and manual shift 6spd auto, go with the 6.7. Its power and torque are very predictable, but depending on how big your boat and camper are, may not have have enough grunt to satisfy your hubby in terms of speed. I know my 6.7 will not pull even close to the same as my 5.9, because of the mods capable on the 5.9, ie chip, exhaust, etc. But if your rigs aren't overly heavy, the 6.7 will serve you great, you cant go wrong.