I agree with you, in 25-30+ knots, I'm on my Mistral Naish wave board of 85 liters, focusing on waves/chop and taking care that my jumps are not too high. 10 years ago, I broke my leg, landing from a jump of > 4m in Cabezo/Tenerife. Now, I'm 44 years old and my wild hairs have been cut in the mean time. So in this conditions I'm not interested in being the fastest with slalom equipment.
The IS101 or F101, I would like to use more in 15-25 knots conditions, mainly with sails 7.5 (NP V8), 6.3 (GUN race/freeride) and perhaps a 5.5. I'm weighing 86kg. In these conditions, when the water is fairly flat (protected lakes next to the sea, as well as open sea), I would like to be really fast. Thinking of buying a GPS as well. I'm for sure not afraid of challenges as long as they stay in my comfort zone, like you stated so nicely. Slogging/tacking is of no importance. I wouldn't be doing it anyway. I'm one of the lucky bastards that can sail in very stable wind conditions of the North Sea (Belgium/Holland). If only the temperatures would be higher, I guess there's no better place for windsurfing.
I'm thinking more and more about the IS101 but the only thing that still bothers me, is that when I sail in open sea, it can sometimes become quite choppy, especially in the 20-25 knots conditions. I'm wondering how difficult the IS101 will ride & jibe in these conditions. My 6.3 gun sail has no cambers. Why is it not such a good idea on an IS ?