The F3HR was a bit of an impulse purchase--REI I believe while on travel to a big city and bored after hours. I liked the all black look. For me the sapphire glass, all black, week or more long battery life and wrist HR I wanted to give a try. The wrist based HR is good for resting or light exercise, but struggles at high cardio unless worn very tight. The HR though and Garmin in general integrates well with Apple's Health app and ecosystem. Check out DC Rainmaker's in depth review of any of these devices you are considering but be prepared to read 40 pages or more. Thinking about selling the regular Fenix 3 actually. iPhone notifications are simply flawless on all 3 devices and GPS (only smart recording on the Vivoactive) is very good though some perfectionists will say it isn't particularly near heavy tree cover. The absolutely perfect combo IMO for running--indoors or out is the Garmin device (any) along with the Scosche Rythym + worn on the forearm (again, check out DC Rainmaker who is a well know triathlete and the Scosche is his regular user). Apple watch is simply a nonstarter for me due to battery life, cost, the relatively light construction and the not always on feature since the screen sucks battery. The transflective displays of the Garmins are far superior for actual use to me. Below are a couple pics of the F3 and F3HR showing off some of the watch faces etc. you can play with using ConnectIQ. Silver bezel is the F3 and black is the F3HR. 7.25" wrist size. Good luck.