I had the 9sqm out a few days ago in +20 knots conditions. Im 78kg and did use a normal board. I compare it with my Best TS 10sqm and a 10sqm Baddi 2015 I did fly recently.
I was looking for an airstyle kite in strong winds and I can tell you the Boost 9sqm does this job! you get up smoothly and glide down slowly (no comparrison my open-c wakestyle kitesi in this size where you drop like a stone...). It also takes away gusts smoothly and did have a very nice turning speed for kiteloops.
I still want to compare it to a Screamer 10, but its difficult to get one.
This kite has a lot of power the low end is very good, and the hang time is insane.
I started with say 18 knots and I could barely handle the power of the kite it was very hard to hold the edge. But later the wind dropped and no body was kiting anymore I could still go upwind and do tricks.
I weigh 68 kilos had the flyradical 2009 128 x 38, I used a north quad bar with 25 m lines
And micro hook
The kite was really slow though, almost to slow to get good jumps out of it and conditions weren't ideal.
strait onshore winds with pretty big waves so it was difficul to maintain my course and head upwind.
I think I have to use the outer bar setting of the bar for this kite to get better jumps out of it.
Or use some of the other settings on the kite to go higher.
There is some setting on the kite which says more or less camber and tommorow I'm goin to try with more camber and outer bar settings. becaus the kite also felt pretty light on the bar.
With more camber the kite should have more lift and bar pressure. Also hope it increases the turning speed a little.