Being both a cyclist, driver, and pedestrian, and passing/being passed by bikes in all modes of tranportation - here are my thoughts.

1. A flashing light in the DAYLIGHT is more noticeable then a steady light. A steady light is more noticeable then no light. While a very bright flashing light might be most noticeable, they also are the most distracting and make judging distance harder. Many of these 700+ lumen lights are basically obnoxious in flash mode. To bad more don't have a pulse mode or low power flash setting.
2. At night I think a bright steady head light is almost as noticeable as a flashing one, and MUCH less disorienting/distracting.
3. A combination of a bright steady light headlight and a less powerful blinking light can be very effective to get attention without being obnoxious.
4. A blinking red light is definitely more noticeable in a bright/busy environment, day or night, but if close at night can be distracting and makes judging distance harder. Some of the rapid/uneven flashing patterns are very attention grabbing. A Solid red light, if bright enough, seems fine in a darker area with less lights to compete with at night. A "Pulsing" red light is a good in between option and helps be noticed while still making judging distance easier
5. A combo of a blinking and solid tail light could be another effective combo

Generally I use "steady" in my front except in daylight or dawn/dusk when I likely use one steady one flashing. I typically use flashing in the rear day or night.