Tom,
The new Flyer Legacy engines all have the Sensor under the Engine except the Y3 that has it under the Tender. So far I have been trying the built in functions that come with the sensor track and they have all worked. (i.e. Have the engine automatically blow it's horn or crew talk when it goes over the sensor etc.) I have not yet tried the recording option but will do so this week. I really love controlling the engines with my iPad. So much easier compared to the Legacy controller especially for others not as familiar with the Legacy controller.
--Rocco--