I've been loving my COROS. It's quite simple, and the battery life is astonishing. No music functionality though, if that's a dealbreaker for you. I got the APEX 42mm about 5 months ago.
I'm in the market for a similar smart watch/fitness tracker and have settled on the Garmin Vivoactive 4. It hits the sweet spot between a sports watch and a fitness tracker for me, plus the battery should last about a week between charges.
Check out Garmin, tom-tom
a variety of garmin watches have gps, built-in maps and music