I think small and mid-sized quads have dropped in price / increased in quality because of the fall in the price for gyroscopes, accelerometers, and ICs that can

I think small and mid-sized quads have dropped in price / increased in quality because of the fall in the price for gyroscopes, accelerometers, and ICs that can do decent sensor fusion. If you have ever broken these parts, you know that quadcopters are effectively impossible to fly. As for the preference over helicopters, multicopters all have fixed pitch rotors, which are cheaper. I think they also benefit from increased mindshare given UAVs in the news.