Full Contact Twists at 1:10 in the video.
My experience is that they are a good/great exercise, but I do not know if they outshine other good/great exercises. Of course the disclosure here is that it has been a while since I did them and I never worked up to any really impressive poundages so it could be that the magic happens at a level I never reached.
If you were going to do them I would get Pavel's material on them and pay attention to form. If you cheat the movement it loses its value and becomes an injury factory. The perceived value is that it is "anti-rotational training" so the pivot on the feet move the trunk as one piece through the ROM. This kind of "body is one piece" training (rights reserved for Dan John) is great.
They are worth trying as long as you go form first and you are already fairly capable of other static "core" exercises. If you cant do front planks, side planks, and hold the top of a 45 degree hyperextension with good form for 60 sec. I would work on those first before you get fancy.