KRviator:
But I feel too many people worry about the sky falling if you lose GPS reception. The chance of that happening on multiple devices simultaneously is extremely remote.
However the probability of catastrophic failure is not zero. GPS can also be jammed....or deliberately degraded.
My point is that if you have ever had a sophisticated GPS/autopilot/flight director system fail on you it is an extremely disturbing event if you relied on it totally. That is if you even have the skills to determine you are being sent duff information.
Unless you learn to establish your position from first principles you are in a world of hurt if the system fails.
Or my BFR (VFR) the GPS was turned off for good reason.