I often ride in town, and the light output is really bright, making me feel a lot safer when the roads are busy. I haven't used it for long enough to realistically assess the battery life, but from the stats, it appears that the battery life is pretty long. I like that it has a USB recharger.
I had a little bit of trouble finding a place to put this on my frame. With my handlebar wrap, it didn't work on the handle bars, and I wanted to be able to reach it while riding so opted against the front fork. I ended up using two of the rubber bands to put it smack-dab over the logo on the front of my frame (sorry, Specialized).