So I am living a pretty amazing example of how the new Find Me feature works.
Today I flew across the country and made a connection at Dallas/Ft. Worth. I had a short connection and my connecting gate was a long way away, and in my rush to get off the plane, I stupidly left my iPad on the first plane. I didn't discover it was missing until I was on the second plane, and it wasn't possible to get back to the other side of DFW to try to retrieve it.
I had put the iPad into Airplane Mode, as required by law, at the beginning of the flight, but I actually didn't use it, so it was still in Airplane Mode. I thought there would be no chance to use Find My.
But lo and behold, Find My worked. It showed that my iPad was still at the gate, on the plane. And then a little later, my iPad was over the Gulf of Mexico, so I did some detective work and discovered that "my" plane's next flight was to Guatamala. Sure enough, a couple more hours passed and it showed up at a gate at the airport in Guatemala City.
Now my iPad is at a hotel in Guatemala City. I'm hoping that a member of the flight crew has it and that perhaps I will get it back. If a passenger took it, I don't expect I'll see it again.
I'm obviously dismayed at losing my precious iPad and at my stupidity for leaving it behind, but it's fascinating to be able to watch its journey and see how this very unexpected technology works.