Bought the watch mostly to replace my garmin vivosmart for activity tracking, mostly for walk, jog, and bike. Mainly for its fitness tracking capacity than trend or fashion statement. I started to have problem the garmin, where it doesn't respond to the taps, it doesn't really do biking either. So I figure it's time to do it. First day out with the watch for tracking. I get about ~37% batt left when I get home. I originally thought I should exchange this for the 42mm for slight battery capacity, but I really like this size better. I have 180mm wrist size. I gotta say it's pretty nifty! Pretty easy to read, it syncs quickly. Garmin band and its app often wouldn't sync, have to close it and start it back up before it transfer data. it says here 12 hours standby, that's about right between the time i left the office and back home. using the bike activity, it's very accurate. the distance is known with my bike computer, and it matches here. the bike thing is very useful to me since I usually have my ip6+ with me anyway when biking. I don't really need detailed heart rate, average reading is good enough for me.