with the dji phantom now at version 4 which you can buy if you can get a mortgage or sell a kidney, i think it was time ben built another quadcopter or multirotor maybe 6 props would be better, but instead of just building a quad you design and build one that starts off basic using a raspberry pi 3 for it`s brain, and you build it in such a way that people can add to it later with things like a gps unit, a compass or even a voice controlled controller, i know things like this ain`t easy but how many people can shrink a speccy down, if you need a pi 3 i have a spare one i`m doing nothing with, or if a quad like this requires a more powerful small pi like computer, i have a pine 64 currently unused, if interested let me know.