When I first started trying to hover, using an own-designed funfly, I began to think it was impossible - and I just knew it was the model's fault. Out of curiosity I mounted a HAL2000 in the wing ("looking" through small "windows" of clear film in the top and bottom of the wing) to "prove" that my model wouldn't hover - and it hovered just great!

My favourite trick at the time was to get the HAL to hold the hover (rudder and elevator of course) and then apply full aileron to "spin" the model - this looked particularly impressive on windy days when the model would drift down-wind spinning like a top

Having proved it was me that couldn't prop-hang, and not the model, I then set-about learning to do it without the HAL's assistance. Nowadays I don't need any gyros or auto-pilots, but I think I might have given-up trying to learn had I not seen the model hovering perfectly under auto-pilot control