This type of hitch allows you to pull dramatically heavier trailers for several reasons. One, the hitch is mounted directly over the rear axle instead of at the rear bumper and this provides much improved stability and control. Two, the tongue weight can be much higher because of where the hitch is mounted (up to 25% of trailer weight compared to 10% for receiver hitches) which also adds much stability and control. All of the “big rigs" on the road use 5th wheel hitches.