I cannot find anywhere whether you are to fly with all off,  any of them turned off?
Did I miss this somewhere on instructions? I thought I had read somewhere on these forums people using their 3G/LTE signal, bluetooth turned on... What if you are flying close enough to your own wifi signal from a hotspot? Or if you are flying from your house and can get that signal?

How do you fly?  
What is your experience? Any downsides you have noticed?

My experience is the wifi or Bluetooth may have been responsible for video glitches and could interfere with tx signal. You do not require either on your iPad to fly with a cashed map. So it likely would be best to disable using airplane mode. Wifi signals from houses and coffee shops deteriorate rather quickly unless you are flying in the building that has the wifi signal I would not be overly concerned.

Thank you for the reply,