Thanks, that extra info makes a difference ; gusty inland conditions, freshwater and flat water all are classic indicators for "one board size bigger" (than typical). With a sailing style also emphasizing upwind range and speed, that is another classic pointer to taking the bigger iS101 rather than smaller iS94 option. In that mode there are a number of advantages to iS101. If you were in solid, fully filled in wind conditions, flat water and going for broad, downwind speed, it would be the other story. With 6.5m and 7.8m, you are certainly well in the iS101 sweetspot (esp considering all of your specific conditions etc.) Advance with confidence.
Sure. Yes, the 230 is definitely based on a lot of input from C3 speed fin development, and here (and on the fin) we'll give Boogie the credit for that ! Basically most of the hi speed testing for the iSonic X / iSonic 50 and other derivative protos has been done using fins either of C3 manufacture or based heavily on the C3 concept. We made a number of versions in BKK and trialled them all specifically at ThePiT. The pure custom fins are very impractical to reproduce in "production"; yes, we tried but it really is such a personal craft and design tolerances are so specific and fine that it is very hard (near impossible) to translate perfectly. The production 230 is a hybridized version, built using production moulds, materials and custom layups, falling short of the full custom (C3) technology and finish, but optimized to give a very good performance in the iS50. The "esoteric" (steveC) nature of those fins is bound to be a little controversial, even problematic to some users, or conditions- and for that reason it was decided to also supply a more regular small SlalomPro28 fin additionally with each is50, which gives owners both an option and/or the advantage of a regular fin for more conventional or marginal condition use - plus the bonus of the speed fin if/when they really want to push it.
Check the user list (boogie). Yep. That's the one. And still very involved in windsurfing, design and carbon etc. he's still very much involved - although a lot less public than the NZ days. And yes, he now lives (short term) in Switzerland and no he doesn't work for AHD. But that was a good joke. We'll leave it to him to comment further (or not) as he chooses. "Well made" and "esoteric" are definitely the right words.
Cheers ~ Ian