I used the 9.0m Severne HyperGlide but I did not receive my production models yet. That is our foil oriented sail. I have the last prototype of the 9.0m, which is the same as Amado and Matteo were using. My sail is basically the same, they are a little bit softer to pump and easier to handle with a slightly shorter boom than a normal slalom sail. When you are in the air everything feels more agile. The shorter boom gives you more ability to readjust your stance for foil flight. A sail with a longer boom makes it more difficult to tweak your stance. That is why a lot of guys use 7.8m sails or 8.6m. They use smaller sails just because there is a smaller boom. We have a smaller boom with a taller sail. That gave us agility and ease of use. I use the same harness lines and boom height as slalom but many guys go shorter.
I am loving the foil races. Some of the races in Japan were so extreme, I have not had that feeling for a while. It is like sailing on a 5.5m and an 87 litre board but with twenty five guys around you, all crossing and reaching. It was super intense, exciting and full of adrenaline. The format is like Formula because you go upwind, but there is a lot more adrenaline because you are on the edge all the time. Your heart rate must be through the roof. The whole race I am fully pumped up because it takes so much energy and focus. You need to be fully concentrated all the time. Every tiny change in your stance and the way you balance is critical. The gybes in the air are scary but the races are amazing fun!