I've been running recreationally for five years, three to four times a week. Then I really hit it hard on the weekend. I bought this watch two weeks ago because I wanted a simple, waterproof GPS watch that shows current running speed t replace my Garmin.I will start off by telling you that this watch is so much better than the Garmin Forerunner 310XT that I am upgrading from for half the price. Calorie reading is more accurate and easy to calculate. The charger and data cable is much easier to connect and use. It finds the satellite right away without any complications every time almost anywhere within reason. Trees and buildings don't seem to bother the reception. The unit does not come with accessories but has ANT + that allows me to link to almost any other ANT + heart rate monitor, pedometer and bicycle pedal meter or speedometer. Setting up the sensors is really simple. Go to the SENSOR screen in the normal setup. 5 different sensors settings are available for pairing (HRM, CADENCE, SPEED, COMBO or POWER). Select the sensor or combination of sensors you want to use.For those of you new to GPS watches, you should know that GPS watches don't give you an instant pace, but an "average" current pace over some time. This watch changes as I change speeds surprisingly fast. The thing that will sell you on this watch is the easy to use software that it comes packaged with. Just connect the watch to your PC with the provided USB cable and download all the internal data directly. It keeps track of distance, time, calories, total ascent in elevation all on an easy to read graph. High resolution graphic mapping that tells you exactly where you have been in detail. You can document everything about your workout. It allows you to enter more than you will ever need to know, even if you are the most data hungry of all athletes.SummeryCons: It comes in some funny colors and you have to order the black one if you don't like blue, orange and green. It does not come with a heart rate monitor but it does pair easily with most all name brand sensors with ANT+ technology.Pros: Easy recharging and data transmission. Simple set up and operation. Excellent and accurate readings. The software is awesome.