Thanks Ian! Great answers!
Just a couple more questions...
Are you sure that nose volume in sonic 100 didn't do anything special? One thing that I do not like with is101 is pumping it up in light winds (7.6m2) and in choppy water. I find it hard to kick nose out of the water at my weight (80kg) with is101, when the board is submerged. I remember that it was not a problem with sonic 100. Nose was never submerged and I found it much less sticky to pump it up, probably because it is also a lot narrower in the nose and it really cuts thru the water easily.
On the other hand, I tested is111 in those conditions and I found it MUCH better for pumping. But with is111, I could stand on the board without submerging it.
I know this is not a big problem, but I find it very impractical in the light races, when you are somewhere in the crowded space and you make a bad gybe and loose speed (stop planning). I had quite a bit of problem with is101 in this situation, but never on my s100.
To make the long story short...Is is96 easier to pump it onto a plane in light winds (med 7.6m2 conditions) than is101? Sonic100 was easier for me...
One more question... Should I use bigger fins with is96 than with s100? SL2 36 was enough for me in light wind with s100, do I need 38 for is96 (wider tail)?