I answered the question but it might got lost in all the writing. I write it because that way people can easily see which my answers on the forum are reliable and which are suggestions...
It mean if I answer on real volume of iSonic 122 and that for me it is a semisinker...I have experience about it. If I write something similar about futura...it might not be exactly spot on...that is all!
In fact I thought it will help the people here to sort all the info contained in the forum.
By the way, I do not think you need different boards for for different conditions (not that much)...but I find a difference between slalom and freeride (I compare now a JP x-cite ride and iSonic...and there is the difference big)...and than it is your choice what board and how many do you want/need.
PA 86 & eVo 100 (with S-1); iS 101 & 122 & 144 (with Overdrive)