The black rubber caps (switches) can press a little hard. Further, gum in the kitchen area (fat, spices, flavorings) in this application is not so suitable. Better would be VA-steel push buttons. Although they have not optically as the Pep, but are more hygienic and easier switchable.
The ground material, where it is taken from the mill, ie directly in front of the grinding stones (rolls) could be more easily detected and inveigled into effect. It happens that one resp toss briefly. must shake to set the grinding process in motion. A slightly conical entrance to the plant could solve the problem. Already clear that this lack also depends on the nature of the ground material.
My criticism would have been softer if the set would not be so very expensive.