Thanks for posting that video link!
I've flown several 4 person team demos wih Steve Shapson using the Force-10 stunt kite. We flew on 150 ft length x 300 lb line.
I've owned 3-4 Force-10s but sold them all over the years. Now, I actually have a another one heading my way this week in the mail. Can't wait to make some noise and get back to some strong pulling, old style flying!