that video is extremely impressive
ive done a little experimentation with this with just a barbell in hands after watching a video of louie simmons explaining how he believes them to be an excellent predictor of speed under the bar (particularly in the catch of the o-lifts, which has always been the worst phase for me)
i always land in the catch position of either the clean or snatch and hold there for a hold so i cant quite compare to that video, but i have also found a great deal of variance in my performance day to day.
i think chris colucci is probably spot on on this in that it takes an extremely high rate of force production to execute, which requires coordinated large scale motor unit recruitment. ive always found that speed is the first thing to go when im even a little fatigued so i save these for special occasions or when i fall into old habits of not jumping under the bar enough