Plummet said..
you must have puissant winds kamikuza. in saying that I have used my 8 and 6 for a while. Mind you there has been half a doz time this year its been too windy for the 6m!....
- and I'm heavy. And the lake is choppy as a bastard - in Thailand, the dead flat water gave me another 3 or 4 knots on the bottom end, I guess.
Here are my sweet spots*
10-15knots, Speed3 21
15-20knots, Flite 17.5 / Speed3 15
20-25knots, 2011 XB13 / Speed3 15/12
25-??knots, 2011 XB10 / Speed3 12
IMHO there's no point hanging on to a kite way over it's wind range, as it starts getting well out of it's design envelope and stars misbehaving in a dangerous way eg. XB16 - Cab says 6 to 16knots, I can ride it to 26 but it starts twitching.
* for the TTs. The boards I have most experience with are Flydoor3 170x50 and my now-lost Flyradical3 138x42. I'd ride the 'door down the bottom end but as soon as I could easily go upwind, I'd swtich to the Flyradical and that'd give me another 5 knots for gusts, I reckon.
Now I've replaced the Flyradical with an 2014 Aboards Z-series 140x43 (don't like it, tips are too narrow for my taste - it's for sale, btw) and just got an Ocean Rodeo Origin 142x47, which looks like it'll do the job. If it doesn't - I'm going to get a Flyradical4 XL

sucks not being able to demo gear...
Got a Dialer too... still getting used to it. Bottom end isn't much more than the Flydoor, but it's more fun to ride. I need better kites for it though!