The power to weight ratio in those models is extraordinary. I take my hat off to the folks who fly them so well, it is very hard (for me anyway) to get used to the lateral inversion and the mental conversion you have to make when flying models and having to do that at such a high relative rate of speed is really impressive.
My AME sells flying helicopter models in his surgery and I have ended up sitting flying one (in a mediocre manner) with his blood pressure cuff on my arm. Nothing like the model in the video of course...
Thoroughly enjoyed that video. Thanks for posting.