Last fall, I started running the Planet Bike superflash "Turbo". It is the same casing as the superflash, but it considerably brighter. Like, wicked bright. It uses two AAA batteries. Battery life seems to be about the same, perhaps slightly less than the standard superflash. The flash pattern is more randomized, sort of like a flashing emergency beacon.

This is way visible at night, and visible on overcast days. One of out local LEOs asked me, somewhat cynically, if I had a Sears Die Hard somewhere on the bike.