Whatever light you decide upon, make certain you know how long the battery will last before you purchase it. I've the Stella Vis 360 helmet light that I use - but the charge really only lasts about 55 minutes. It is USB chargable and comes with a large red flasher for the back of your helmet. It is very easy to put on/take off your helmet.

Bottom line, if your commute is under 1 hour this wouldn't be a bad choice. If it is longer, then you would need to use one of the lower light settings to conserve the charge and I wouldn't be comfortable with that. It is bright enough at the highest setting, but not so bright that I would be comfortable using it in the country away from ambient lighting. There is lighting on the side of the front light as well, which helps to increase side-visibility.