On typical Tech21 cases the entire case is flexible plastic. This case for my S7E, is more rigid, with the exception of the top and bottom where that white Flexshock material is, it if cushiony and flexible.
Those are hybrid cases...typically polycarbonate backs and TPU sides and bumpers. Not a big fan of the frost look but it hides fingerprints better. Tech 21 is pricey I think? I usually look for bargains or perceived value. But if you like it and it provides the amount of protection you want, that's all that matters.