Wow, great replies thanks! I agree with those who don't like a solid steady light, it doesn't seem very useful, especially in daytime. And at night, a solid red light may look like it's just a reflector on the side of the road on someone's mailbox, to a car. Definitely need the flash mode. Any flashing mode that has an "off" position is the least preferred to me, and if it's regular, it again seems like it would not be as effective. It seems like the randomness of the flashing, plus the brightness are key. I'm just starting to use this light in full darkness, so I'll do some experimenting, but the rapid mode (semi-random and intensity change) and vibration mode (very rapid flashing) seem like they'd be the best.
Also, for the front, I decided to use 2 lights. My Volt 700 for steady light, and another less bright light set to flash. At night, it's just too distracting to have my main light flashing at all, so the more dim one gets washed out in the intensity of the main light, and doesn't bother me. But (I hope) the smaller flasher should act as an attention grabber to cars.
Lastly, I have amber spoke lights on my front and rear wheels for a bit more side viewing. Combined with a retroreflective jersey, I was pretty impressed with how cautious cars were around me in almost total darkness. This is my first winter of trying to do dedicated rides after dark, and I'm actually looking forward to it.
Last edited by cthenn; 11-04-15 at 05:05 PM.