+1 I've got 2 re-chargable steady beam lights and one flashing that requires 2 AA batteries. The flasher is used during the day and the steady beams are used at night. Sometimes togther sometimes one at a time. They're 10w halogen each.

It terms of being rude or not if one is on a club ride flashing lights can be annoying. But, when commuting one wants to be seen, rude or not. The brighter the better on flash mode. Nobody gets hurt and it may save your life.

If riding/commuting on an MUP it would be best to have something like a Cygo-Lite 12w dual HL. It has 2 lights that're 6w halogen each. That way if you're running on 12 and someone yells at you one of the lights can be switched off and you still have enough light by which to see.