As most of you know - typically vehicle lighting needs produce lights that need to compromise between "flood" and "spot" patterns. And typically this means that "flashlights" always have tighter "spot" patterns than "made for bike" lights.
My own experience suggests that a good multi-cell 800 lumen flash light is effective when mounted in a manner that afford me the ability to point it into the eyes of oncoming motorists that fail to dim their own "ffff-iinng head light."
Other than that - I don't see much need for spot lighting........ Well - maybe on a high speed descent...... blah blah blah ....