The insert discs are very well designed with great 4x4 adjustability. There are 4 increments and 0.5" each available to custom the stance. I really appreciate this feature. The discs also come with two holes for The Channel System. Although the flex is 5 like medium flex, I felt stiffer than that so they are more responsive than I thought. Two areas need to improve with my personal opinion but they might not bother you. 1. The base plates are well made but I had what difficulties to put them back on after installing the discs. One foot is okay but the other foot gave me some hard time because it took me a while to hear the "click". 2. The high back female screws need to be tooless as they require one more screw driver to hold in order to rotate the hight back. Overall, they are great bindings in performance but need to have better design for installation