Originally Posted by lviz
I've been using Garmin watches with Samsung phones for some years now. The Garmin app is not a battery drain and doesn't use much data in day-to-day use. This should be true for Essential also, unless there are bluetooth issues in it. The Garmin app has evolved quite a lot and is pretty good these days. It used to be pretty poor back in the early Vivoactive days.
One thing to consider is your use of a smartwatch. The Garmins don't do as much as proper smartwatches, but you get notifications from the phone, can do some music control etc, and the training tools of your chosen model. You also get significantly better battery life. The original Vivoactive needed charging perhaps once a week in my use, my current 935 goes 1.5 to 2 weeks on a single charge in mixed use. There are Android Wear devices that have wider app support than what Garmin's devices offer, but you lose the battery life etc.
Thanks lviz - I don't have any particular make or model in mind yet, but I've heard lots of good feedback on both Garmin and Samsung watches. The bells and whistles are nice to have, but I'm primarily interested in time/approximate calorie burn and HR. The HR doesn't need to be accurate to the beat, which is good because I just don't want to wear a chest strap.
I'm still undecided on the phone too. I loath the thought of spending on another iphone, but I lose a couple hundred dollars in iOS only apps if I don't. At this point my 6+ is still stubbornly chugging along, so I'm thinking Christmas sales now. We'll see ...but an Android device is almost a sure thing at this point. iOS 11 turned me off of Apple that badly.