but as good as these units are, they tend not to have a wide range of
flash modifiers, but worse, they are not compatible on different brand cameras, so if you use a compact Olympus for social events and a Canon 1D for serious work, and a Bronica medium format film camera for fun stuff, you need a different flash set up for each, which not only is it expensive, but it means you have to have duplicate setups if you are taking the same scene with different cameras and its more to learn the vagaries of each system.