As said above, they did beef up the core and press them slightly differently than last years, it leaves the skis less prone to delam. They also added a TPU top sheet which chips less, it's almost like a rubbery feeling material.
Bottom line, they are an extremely fun and great ski. I rode a pair last year and absolutely loved them, super light, super poppy, and I enjoyed the small waist width, really gives you a sense of what is actually under your feet. Whatever year's model you go with, I guarantee you would enjoy them.