Just like the non Fast Charge model, instead of a flash, this light has a fade on and off mode which probably won't earn the attention of drivers who are busy texting while they drive. If this is your only front light and you value flashes, I would skip this model (though there are others by light and motion that will fit your needs).
I am using this as one of two headlights on night rides (one light is dedicated to flashing and pissing people off with the "Urban 400 series" while this one is to provide light to see the actual road so that I don't nail potholes.) Over kill? Maybe, but it's my life right?