Hi, I consider myself an intermediate runner. I run between 80-130 km a month. I used to run with my iphone 5, a bluetooth Polar heart rate belt, Runkeeper app on iphone, and listening music during the run with standard connected earphones. I bought an apple watch to simplify the process. I received my 38 mm sport edition last friday. For an optimal run, I need basically music + 4 parameters ideally at anytime : time, speed, distance, heartrate. Apple watch is almost there. The only advantage for the Runkeeper app on the watch is to start and stop the run easily from the watch. The watch heart sensor is not transfered/connected to runkeeper. So I prefer the built in Workout app instead of Runkeeper app since it detects the heart sensor (no more polar belt). I ran 3 times with the iphone(gps) for the initial learning of the stride length. The workout app shows 2 of the 4 parameters I need at the same time. I don't understand why it can't show all the 4 parameters I need at the same time. I guess that would be fairly easy to develop; maybe the battery is an issue to update these 4 parameters in real time on the same screen. The total distance is exact (using iphone). The heart rate is apparently exact with a decent refresh rate. I will progressively remove the iphone to see the distance/speed results with the watch only. For no apparent reason, the average heart rate isn't showed in the archived workout data on the iphone. I need to access to the cardiac frequency record on the health application for each minute of the workout. So for my case, the almost perfect running solution needs : - 4 parameters showed at the same time on the screen (time, distance, speed, heart rate) - Archive of all this data ideally on iphone on the same record - Ideally indexed path and elevation if I used an iphone/gps. Alex.