Since the tongue weight rests directly on top of its drive wheels, rather than on the back bumper, there is less stress on the towing vehicle's frame. You should have better front-wheel traction with a 5th wheel because the weight of a bumper-mounted trailer can cause the front of your vehicle to raise up.
Drawback---you lose most of the cargo capacity in the bed of your truck. Even when you're not towing, there's this big hitch in the middle of your truck bed.
Thank you - that makes sense. Can you make tighter turns with 5th wheel?