After subjective feeling mean noise.
Length of the 12V cable is sufficient in any case loose with a 4.56-meter car with estimated valve distance between front and rear tires of about 3.75 meters. Maybe, but an extension would be necessary in a Jaguar or minibus.
The comments of Vorbewerter the screw must be confirmed, but it also eliminates the susceptibility of folding shutters, partly because of the need to use force during unlocking what certainly causes many valves air leakage due to their instantaneous angle adjustment.