Hell of ride. Zero to about 40mph in a second...
I believe I saw a show on Discovery where they had a roller coaster powered by this technology. I could be wrong.
You are correct. They have more than one running in the US and maybe more in Europe. They reach speeds of up to 90 miles per with the magnetic propulsion on Roller coasters. This is also the same type of technology, the basis anyway, of the Mag-lev trains that have been built in various places.