I'm using the IS122 (2008) from 12 knots. I'm 86 kg.
It handles perfectly a 9.5m2 sail. Without any problem.
When the wind picks up I also use a 8.4m2 (it's really the sweet spot for me) and even a 7.5m2.
Afterwards I'm on my IS101.
The IS122 is a great light wind board, but I need 12 knots with my weight.
Below this, I'm on my formula (recreational sailing, no competition).
IS87 / IS101 / RRD114 / US147