Which one would you choose? The double leg is often considered the easiest and fastest. But first, I would really have a problem dropping my forward knee on conrete in a fast movement. And second, if it fails you are f'ed, because you opponent is standing and you might be eating knees or a head kick. Judo throws which are executed in a more upright position might have the problem of getting close enough w/o eating too many punches. Or even a knee to the groin. But what do you do against a bigger, stronger opponent whom you might not throw so easily and who is trying to hit you anyway? Is there a double leg without the knee drop?