Randal you are quite right about smoothness of operation, but those out there in the market currently that I have driven are not the best....but we are making steps in the right direction.
Electro-mechnical (Hydraulic) systems can be designed to allow the brake to be 'pumped off' using the steering system in a manual mode for pressure, which means that even with a dead battery the machine can be moved.
This is ONLY to be used to report flooding, spam, advertising and problematic (harassing, abusive or crude) posts.