I have the Sonic 2 9m and the Sonic Race 7m, I have all of the Sonic 2 kites. I don't find that the 9m really flies any different to the 11m other than being smaller. I find that the wind is a little more gusty when higher in the places that I fly it. I have been using shorter lines on the 9m, 18m lines vs 21m with the Sonic 2 11m.
The Sonic Race 7m is lighter and sometimes if I am traveling and don't think it will be windy, I can just take the 7m instead of the 6m and 9m Sonic 2. Not a big difference and I think that some of it is because I fly the Sonic 2 kites more and get use to them. It seems to me that the Sonic 2 kites are happy to be more actively flown around, the Sonic Race kites like to go fast in a straight line.
Do you have a 9m sonic2? Some here have tried it and hated it enough to send it back.
I hadn't heard anything bad about the 9m Sonic 2. What didn't they like? I really like mine. It's very stable even in gusty-windy conditions. Maybe others didn't like it in light conditions though? I've only used it in >18 knots.
I never really use it now that I ride my 11m up to low 20 knots range. Above that, I'd rather be on my 8m inflatable because I don't like launching/landing foil kites in over 20 knots. Especially if I have to self land, always a mess with the bridles. There's not much benefit to the foils over 20 knots anyways.
Sonic 1 9m was a handful. Always surging back and forth. Sonic 2 9m as a huge improvement.