I like mine, and have found it has reduced the number of traffic altercations by reducing the surprise element, so it has taken a bit of the pressure off my middle finger. I ride mostly rural roads. It is most useful on downhills or when I am going fast enough that it is difficult to hear an approaching car. On windy roads, a car can be close behind before it is detected. In heavy-traffic areas, the beeping (I have it paired with an Edge 25) can get annoying.