I had two criteria for a watch: it must give accurate heart rate and be waterproof. It IS waterproof, truly. I like the durability and the battery life. The software is informative and easy to use. I really like the sleep monitoring, though it counts me as asleep sooner than I am. Biggest disappointment is that heart rate is not reliable while swimming or in recumbent position, which are the only types of activity I can physically do. It can be literally 80 or more points off at times. Other than that, heart rate is right in line with BP cuff and pulse ox machine.