Yesterday, my first experience with the Ultrasonic (carbon) of a friend.
In 11 - 14 knots conditions, I was struggling a lot with my IS122 + 8.8 sail. On and off the plane, not really amused.
Normally I take my formula + 11 sail in these conditions.
Just when I wanted to go and rig my formual gear, I saw a friend with his Ultrasonic.
He had a 62 deboichet cusom fin, don't remember exactly which one.
He allowed me to sail a few racks with it. Lucky me

I used my Gun 8.8 Mega XS on it.
Result, ALWAYS on the plane.
Big difference (of course) compared to the IS122
My first inpression when sailing the Ultrasonic, I can describe in 1 word: LIGHT.
The board feels so light. It doesn't feel like a 90+ cm wide board at all.
It planes very early.
It has almost no volume in the nose.
I understand now that it is possible to use the board also in rather high winds, just because it's so light and feels relatively small.
The ONLY thing that I regret is that I didn't make time to rig my 11 sail and try it with real formula gear. To be honest, I have the impression that the board feels too light for this big and heavy sail. It's just an impression, because I didn't really try it.
So all of you out there, please share your experiences with 11+ sails !
I'd like to hear much more of this ...