At the expense of a moving part, having the option to close down the aperture will probably improve image quality in daylight. With a fixed aperture, increased

At the expense of a moving part, having the option to close down the aperture will probably improve image quality in daylight. With a fixed aperture, increased low light sensitivity usually brings lower resolution (so called "fast" lenses generally have improved optical characteristics with their aperture stopped down). That is unless these dinky sensors are diffraction limited at f/1.5, which I doubt.