I would disagree with the windchart and say that no-ne of average weight will be well powered on an Edge RX in 11 knots.
However on Tuesday evening in Sydney, I went out for a kite is gusterly southerly at Dolls Point.
Wind was averaging 13/14 -20/22 knots, with approx 2-3 knots of opposing current in parts of the river.
I was riding the stock standard demo 2009 Edge RX 11M.
Rear line trimmers about 1/2 on.
At first I went out on a Calibre 1.33x40, was able to go upwind, but it was not much good in the lulls and I did not want to end up around the groin in no mans land, so I swapped boards.
Then I grabbed my Airush switch 1.46x46 and I was riding well powered to lit, and was able to get some excellent jumps.
Another rider was out ona Flexifoil Ion3 12M, he weighs 30kg more than me and was on an Underground FLX 1.52x42, he was able to go upwind get ok jump in the gusts, but I was able to ride way upwind of him and overall had plenty more power.
So, I guess I'm sticking to my opinion that its techinique and my experience that night really confirmed that. The kite was a little stally when bar was pulled all the way in, but I would immediately let the bar out a bit if I saw that the kite was oversheeting, however when I was powered in the gusts, I needed to hold the bar in to get power, upwind and to turn tight and fast to get the kite to jump.
@ Lonerider, your idea of the truth and the TRUTH are widely different things, your idea of it is just your opinion actually, and thats the truth mate!

Some people say the exact opposite as you say, but I don't call them liars, I just respect their opinion and suggest that they may need to ride differently or that the other kite just does not suit their style.
Cya and
Goodwinds
Steve