They have normal durability. I have never personally ridden them but from what I hear they have a pretty typical weight for the dimensions of the ski. Apparently the swing weight is realy good on them. I almost bought them.
I demoed the kennedies last year, and they were really light and had good pop. Seemed like great skis. I think I heard that they don't have the best durablity from somewhere, but I might be wrong.