The one I linked to looks close to some of the alpine coasters linked here, but I liked the fact that by shifting your weight or regulating your speed you could change how much you banked turns (I’ve ridden it before). There is no connection the track at all. That might not work very well in the litigious United States.
Our friends took us to a huge one in Germany, commonly called a rodelbahn over there I can confirm that they are immense fun. Even more so when you realise that the brakes are simply not needed. We took our little ones on aged 3 and 5 and they loved it.
I went on one in New Zealand that had a concrete track with a similar design to the one you linked to in Germany. You could take a pretty decent flyer off the track if you tried to. I was sitting next to an ER doc on the bus out of town and asked him about it. He said that they get almost a broken arm a day. :eek: