This excellent update features a more segmented midsole under the heel to better isolate and disperse impact. Asics used more gel in the heel to give the shoe a softer crash pad. According to our lab tests, these improvements make the 9 better at shock dispersion than its predecessor. There's also a new rearfoot overlay wrapping the heel that helps center and guide the foot for a better heel-to-toe transition. Recommended for runners with normal to high arches looking for a neutral-cushioned shoe with a bit of added stability.