I have not added one yet but I will be when i get some time.
intended uses being:
-Rear winch moint/pull/anchor/extraction point, my winch is the type that mounts in a reciever and I can imagine using it as a anchor point to assist another vehicle that is following behind (trailer still attached to my vehicle of course).
-Both my Father and I tow trailers behind our rigs when we head out to our secret spot, last time it would have been realy handy to be able to tow two trailers with one vehicle as we had problems on the trail.
I use the one on back of my Chaser for a basket rack, where I carry firewood on long week-ends, or use it as a tow point to extract Jeep if I get stuck..I think it is well worth having a hitch point in the rear.
Towing two trailers is legal in many states as long as you don't exceed some specified total length. So towing a boat behind your trailer could be do-able.