I recently asked my wife to critique my night time gear. I was wearing a reflective/neon vest, had a single rear blinker, and my headlight. She approached from behind and said I was very easy to see. She did comment that it would be nice if I had some sort of light up high to give a better picture of a person on a bike. I have added a blinky up high on my vest. I like this spot better than the helmet, as it tends to point back more, where ones head is moving side to side periodically. Either is better than nothing. Both have the problem of being hard to keep pointed well in the correct direction. But it the rack mounted one stays put (as it should), then the one up higher can have a lower visibility factor and still be effective.