My LAX-JFK flight also had to use the "Plane Mates" upon arrival at JFK last Saturday. The pilot explained that there were no gates available. This was my FIRST experience ever riding this contraption. It was creaking all the way to the terminal. Had fun watching watching many people trying to hang near the front of the door so that they would be first to exit.

I had a similar experience at CDG where they have this type of Elevator Bus.