I went from a polar 360 activity tracker to a fenix 5 as the polar was limited for someone who enjoys multisport and hiking (and has no sense of direction). And I have to say I am pleasantly surprised as well as a little surprised about how a simple activity monitor and the polar app is better in many areas.
I do running, rowing, cycling, weight lifting, crossfit, climbing, yoga, hiking etc. And in all the endurance sports the HR seems accurate. But even with intense HIIT/X-fit without a lot of wrist bending the garmin cannot keep track of the hr, even if I stop and press the watch down to check if it is the fit that is not right.
I tried downloading a map for a 609m stair hike up a mountain and trails on the top, and the GPS and tracking was super-accurate!
With rowing I am a bit disappointed with the options for editing the w.o afterwards with distance, speed etc. as I am trying to improve this.
I think in my case it is not over-estimating the calories burned during a day with steps, but because of the x-fit it is under-estimating it.
I am also finding the polar flow app for viewing HR over time, load etc. much more user friendly than the Garmin Connect app.
The sleep measuring is not sensitive enough for waking up etc. it seems as long as I am physically in the bed it counts as "sleeping". I am not a great sleeper so this is something I tend to look at, but I find I have to edit it every day as it is over-estimating.
Look wise and options etc. I am super happy with my watch, but I though Garmin was like the "mothership" of all watches, so I was not expecting so many hickups and lack of user friendliness in the connect app. (I could mention many more areas, but we all know about these already).
Anywhoo.. just some thoughts.