I thought the redonda is based on the circular/figure eight type striking with emphasis on speed and motion and less on accuracy. While the sinawalli is based on more linear type striking with emphasis on speed, striking points on body, angle of attack, and recoil or chambering of said strike. There seems to be more to a sinawalli in my opinion than the redonda. But then again I've only been doing this for three years unlike most of you, who actually knew the professor.