Think the reply from Cabrinha support is very fair.
I have flown the 9 Nomad back to back with the 8 SB ids in between 16 - 20 knots.
Nomad lighter setting, middle knot. Didnt feel good at all. Unresponsive.
Then launched my SB, felt much better, more powerfull etc.
Decided to give the Nomad another go on 3rd knot for most power. That did it for the Nomad. Quick responsive kite, no backstall, really nice.
Yes the SB has the best lowend. But the Nomad can come really close. It just requires more active riding.
On the other side, the highend seems to be huge

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With that said, i'd suggest to ride a bigger board:
A bigger board helps you get going earlier. Also bigger boards have some other advantages aswell.
Caliber is a great board. Nice rocker and outline to give a good 'freedom' sensation when riding. I would rather stay home than to ride a flatter board

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Im 85kg and riding a 138, and even a 144 board since a few weeks. It feels great.
Remember: You are more likely to reach the lowend of your board, rather then reaching the highend of it.