I also have a Cygolite. Battery life isn't great, but recharging is easy. It is sturdier and more waterproof than any battery-powered light that I've owned in the past. The bright flashing modes are really obnoxious to other bicyclists, so I only use the steady or pulse modes. I also have it mounted to my seat stay, which is less obnoxious to other bicyclists than mounting to your seatpost or (especially) your helmet. Unfortunately, some Cygolite models do not come with the seat stay mount, so verify with your shop before buying.