Last weekend on a group ride I saw one cyclist using a combo red/white very bright flasher on the rear. Didn't distract me and made the bike very visible during the night ride. But some folks seem to be more sensitive than others to bright flashers. My idea of a bright flasher would be what emergency vehicles use - I haven't seen any bike light nearly as bright as a police car, ambulance or fire truck emergency flashers. And we cope with those.