I would say Apple watch since you already have an Iphone. My series 3 Apple watch is still going strong. It was what I first started using as cycling "computer" The cycling portion of the fitness app gives a lot of information such as, total time, distance, active/total calories, elevation gain, heart rate info, avg speed, and a map or the route you rode. There is even a section that will provide avg speed for the splits. As mentioned above it works well with Strava. The only item I can not speak to is the sleep tracking with the watch. I know there are apps I just have never though of using them.