My first flight with GPS off was a fun experience. First off switching GPS on/off several times had no ill effects like movement or jerkiness. It will start to drift a little but it holds its altitude just fine. When you turn it off the ST16 pops up a warning and vibrates to warn you its off. After that hang on it is fast ride, it will accelerate up to 60 mph and it really jerks if you nail the stick. It is fun to play with but the video suffers which is to be expected. Not just from the wind going 60 mph but the motors must really be cranking as you can see the vibration in the video under acceleration. When you hit the stick you can see the camera swing to its end of travel. Fun times, you should all try it!