For me personally, the material thickness of the silicone too thick, which is measured with calipers from 1.7 to 2.8 mm.
Thus, the handle is a bit heavy, which may be for hands> 10 beneficial.
Silicone is smooth, this is also true for this envelope to. In order to maintain the grip attached to the thumb rest and the front handle bow knobs, but do not reach the handle characteristics of the camera far. In fast pan's, for example when shooting sports, or who keeps his camera while on safari like out of the window, a firm grip is already helpful.
I can recommend the sleeve People with large hands and those who leave their camera often pop up stands or car doors. Which would be borne in mind here that the objective then, unfortunately, no "shock" has.