Looks handy, but just remember the people in that seat are going to get crushed in a rollover, and will experience much higher side to side forces than the driver (farther out from the pivot point) trying to throw them out the side of the vehicle in certain bumps. You can't judge the side to side forces from the driver seat, but they are going to move roughly twice as far (in the same fraction of a second, so more than twice the force) as driver does every time the vehicle bumps to the side. Children in that seat are likely to be leaning out the side at the wrong moment.
Of course if you're just puttering around like a hay ride, it won't matter, but if you're on trails like mine it could. Just something to be aware of.