Instructors in my dojo speak highly of Sylvain's aggressive & powerful technique. Its always interesting when someone can use the word "monster" as a compliment.
Based on the small bio you offered, I'm sure you have an interesting perspective on some of the discussions aikiweb has been having the last few years, particularly the 'kokyu wars', and discussions of 'effectiveness' (often in regards to the streets or the need for sparring/ non-cooperative ukes).