I like the heel stability and Torsion vent that keeps my foot cool.

These are very stiff fore for flex and hard cushion. I bought 3 pairs for me and my sons. We play 2-3 times per week. The forefoot gets pinched and very uncomfortable running. The heel is hard as heck and after 2hrs of play, my ankles and knees are hurting. I’ve also bought many prior versions of ubersonics, and those were quite comfortable. This latest version is horrible. Many of my tennis buddies also tried and agree. I’ve stopped playing in them for fear of injuries. I can’t believe the other ratings that these are comfortable.