As a motorist ( which most of us are anyway) I am not too sure its any particular headlight that attracts attention any more or less than the high visability clothing worn by the cyclist. I dont even like to run over traffic cones knocked into the road let alone a cyclist...I have no great problem seeing their reflection.

What is annoying is the habbit of some cyclists taking the right of way at speed on pedestrian crossings t junctions etc etc...... OK it might be their Right of Way but they dont want an epitaph I Was Right.... rather a safe journey.

Also in my experiance it's a brighter rear light or bigger red reflector that would provide more safety. I do think the little flashing lights get noticed more...

With urban lighting most of the time there is so much light polution some motorists dont even know if their lights are switched on or off.... Unfortunately this applies to indicators too..... But hey who indicates for a lowley bicycle ???

So wise up on headlights by all means but first get the clothing that gets seen... next the pedestrians will be wearing headlights... lets see I could run to work reaching speeds of 18kph.... I need 5000 candle power etc etc.

Now come on which realy is the best lamp without taking out a bank loan