Since none of the "team" have replied here's my advice for what it is worth. I just tried the Isonic 133 - now that's a light wind machine. I own the Isonic 122 and the older Isonic 135 and the 138 Free Formula (96 cm. wide - a little wider than the FType). The 138 Free Formula (if you can find one) has a huge wind range and a very fast top end and would work well in gusty 5 to 20 knot conditions (what I often sail in). For those 5 to 12 knot days the Isonic 133 should be lots of fun - at a weight of 150 lbs. the 122 would work well too, but you'd probably never come off the plane with the 133!