Imperfect but ...

Obviously for the price, you could not expect better. We must set the counterweight properly position his camera (note the weight of it, beyond the conventional compact cameras I think it does not work anymore) and try not to move violently because then the stabilizer will not be efficient.
Similarly, it is really effective on the horizontal axis (X), less on the left-right (Y) and not at all on the vertical axis (Y). However the image is undoubtedly see a softening of movement which makes them much more watchable movies even if it not reach the performance of the pros.