+1 I do run a cheapy Cateye EL135 as a second light at night and at dawn/dusk, on flash mode. I don't get to ride on any bike paths on my commute. The reason I like the flash mode is that much of my 13.5 miles each way consists of riding through older neighborhoods. The flash helps me stand out in the midst of the trees that have rising or setting sun shining through them. This is especially important in my situation when drivers are backing out of driveways.

If I did get to ride one of my area bike paths on my commute, I'd only run my solid light and leave the flasher off.