The one thing I didn't like was if one air bag goes that trailer would slam to the ground. On semi trailers they mount underneath so the trailer would just rest on the axles holding the trailer up allowing it to still roll to a safe stop.
That style of trailer is fairly popular with the low slung land speed cars, steamliners and lakesters mostly. I'm pretty sure they have a safety pin for a "just in case" moment. Neat as hell and definitely a conversation piece.
Just picked one of these up the other day for my brother. Towed my Camaro on it pretty nice. Does need the switch to lift up near the drivers door so you can raise it whilst in the car. Has a safety pin you release to lower it and lock in place when driving. Secondhand paid 5k.