Not sure which butterfly display we are talking about, but the rectangular display that comes with the brick is anything but *useless* to anyone flying with polarized sun glasses. It is polarized incorrectly which means if you mount it in horizontal orientation you see practically nothing on the display. Unfortunately neither the manufacturer nor PowerFlarm folks think this is a problem. The best answer I got was "this is not a problem, don't use polarized glasses"!!! I don't have that problem with any other avionics.