I had a 2012 isonic carbon, like you hated it... too hard on ze knees !
Went on to Patrik boards with much delight for a few years.
then, this year I demoed a 2017 107 isonic reflex (full carbon), what a change !! Smooth, forgiving, soft on the water and bloody fast !!
had to buy one ! awesome board, can't imagine the reflex being worse