I really needed it when I was getting back into riding. I really use it when I am doing any sort of training, whether it is hill repeats or perhaps high cadence (115-120) intervals. Also on longer rides such as centuries I look at cadence and heart rate to pace myself, especially on climbs or even high speed flats. Today I don't need it to do a typical club ride (40-60 miles), but it's there and I use it.