I had the Garmin Vivosmart HR for about 10 days and am writing this review which I hope might be useful for people who are interested in purchasing the device. If you regularly run outside and need GPS functions, this fitness tracker will not be adequate do for you.

The Vivosmart HR is the first of Garmin's devices to offer "Elevate" heart rate monitoring technology; Garmin's own in house tech and not something borrowed from Mio Global like the Forerunner 225. I suspect the Vivosmart HR work on "Smart recording" basis; the HR data is not captured per second but at various points during your workout or run where there could be a change in pace or direction and so on. The HR could be read once per second to even once every 7 seconds. But overall, it forms a good picture of your heart rate trend during the tracked activity. You can check out the picture I attached below of the Vivosmart HR compared against a Polar H7 Smart Bluetooth chest worn HRM.

To get an accurate reading, strap up tight and above the wrist bone. Sometimes I wear mine on the inside of the wrist during exercise and it's more convenient to "look" at without having to turn my arm at an awkward angle.

HR is also tracked 24/7. The data is then presented in Garmin's mobile Connect app. I'm not too particular about the 24/ HR since I don't strap up tightly when I'm not engaged in work outs. Also you can't pair an ANT+ chest heart rate strap to the Vivosmart HR though you can broadcast HR data via ANT+ from the Vivosmart HR to compatible devices such as Garmin VIRB camera.

The fitness device also tracks your daily activities such as steps, calories, distance, sleep, active minutes and stairs climbed. This is like a Fitbit Charge HR but with more functions and smart notifications. In order for stairs climbed to count, the difference in elevation between levels must be at least 10 feet, that's Garmin's benchmark of a flight of stairs. Sleep tracking is automatic but you can manually edit the data if you take naps during the day.

During tracked activities such as a run, the Vivosmart HR will estimate your distance covered based on the accelerometer. It's merely an estimate and I would use the distance as a gauge at best. Nevertheless, it's better than nothing.

The display is always on and I personally found the display great in the day and a tad dim under low light conditions. The brightness level cannot be adjusted. Thankfully the orientation of the display can be set to horizontal or vertical; that made the fonts appear slightly larger or smaller. There are multiple levels of customisation. For example, you can set the stats you would like to see displayed during workouts and also the orientation of the display.

In terms of smart notifications, you will see incoming calls which you can "pick up" from the fitness tracker though you'll still have to speak to the connected mobile device to talk. Notifications from most apps will also appear on the display and can be expanded so you can actually read the entire message without having to take up your smart phone. This feature works most of the time. I've personally encountered situations when I just couldn't expand the message and I have no idea why. And no, you can't reply with pre-set messages.

You can also see weather (when connected to mobile device), use the Vivosmart HR as a remote to play music or control VIRB cameras, activate the "Find my phone" function, set alarms or receive "Move" alerts when you've been idle for 1 hour.

The strap is non changeable so you have to choose the colours wisely. Battery life lasts up to 5 days and it's about right. It will likely be shorter if you track your exercises quite a bit or have so many incoming notifications that saps the battery due to vibrations. Charging cable is proprietary.
Water resistant is rated at 5ATM.

I thought Garmin's Vivosmart HR should more than suffice for those who are looking for an all-in-one fitness tracker without GPS capability.

Here's the list of features for ease of comparison:
Pros:

24/7 activity tracker. Measures steps, distance, calories, heart rate, floors climbed, active minutes
Measures heart rate during tracked activity sessions
Always-on sunlight readable display with back light
Smart notifications
Vibration enabled for alarms and move alerts
Remote control music on connected mobile device, Garmin VIRB cameras
Find my phone function
Waterproof to 5 ATM
Up to 5 days battery life
Autosync

Cons:

Non changeable strap
Dim backlight

I wanted to write a review on this because I feel like people who leave reviews of this product haven't given it a reasonable amount of time to become acquainted with using it, therefore unfairly bashing the product.

My specs:
I am 38 year old female, 161lbs, Beachbody on Demand user [Challenge du Jour program (means blending of P90X, Insanity, Hammer and Chisel, etc workouts = 6 days per week, Sundays off.) I love workouts that burn over 350+ calories in 30+ minutes]. I surf. I do not run. If you are a runner, you'd probably want a watch with GPS. I am not a runner so I don't need that feature. Vivosmart HR was purchased from Best Buy on Oct. 27, 2015.

I absolutely LOVE this watch! I used to have the vivosmart band + chest strap and found it to be extremely glitchy and a pain in the ---- to use the heart rate monitor during my workouts - as for the vivosmart band itself, I really liked it.

These activity monitoring watches take some time getting use to and understanding what the symbols mean - just like when you first get an iPhone or smartphone, at first you don't fully understand the flow of the buttons and apps until you have used it for at least 2 weeks. That's a smartphone...this is a smartwatch. With this Vivosmart HR watch, you should allow enough to become acquainted with how it logs information your body sends it. This watch has a heart rate monitor built in AND is water resistant. I have used it to go surfing with and it works. It is secure and comfortable on your wrist. I could not live with a watch that was not water resistant. It would not work with my lifestyle.

I've bumped the screen a few times against hard surfaces and it hasn't scratched; a great feature for me because I am not delicate with my things. I like durable. It is quite streamlined though so it does look nice with a dress on.

Heart Rate Monitoring:
Your heart rate is read every few minutes while NOT in ACTIVITY MODE. This is to conserve the battery and because while you are not in an activity, usually your heart rate remains somewhat the same.

Before you start your killer workout :) ------> Tap the side button, tap the Running Man icon, tap the side button to start: Your Vivosmart HR is now in ACTIVITY MODE - While in ACTIVITY MODE, your watch will read your heart beat every few seconds and measure your calories burned + more. You can tell when it's in ACTIVITY MODE because the back-light will be on for the duration of your workout. While in this mode, you can swipe and choose the screen you would like to continuously view during your activity. I always like to keep mine on the heart rate monitor screen because I like to see how hard I'm working and if I can max out just a little more [I'm at 148bpm? Bah! Let's get to 170bpm! More squats!] When you have finished your workout -------> Tap the side button, then tap the little disk icon to SAVE your workout stats.

The heart rate monitoring on my wrist works great. I found that you don't have to wear it super tight for it to take an accurate reading. I wear mine 2 holes looser than what could be tightly flush around my wrist. The only time I find it to not function properly is if I haven't washed the watch with a mild dish [like Palmolive] detergent for a while (3-4days) - I take the watch off and wash it by hand in the kitchen sink. Makes sense because I am sweating a lot during those days and the screen should be freshly cleaned with more than just shower gel.

The Garmin Connect app:
Is great! Garmin has been doing a good job of making it better with each update. All I really care about is heart rate, intensity minutes, calories, and sleep data. All of the other features of the watch are quite accurate. I don't have stairs so I can't speak for the stairs, however the steps counter seems to nail it every time. This watch calculates calories burned throughout the day accurately.

Garmin Email Support:
Is AMAZING! When I first got my watch, every time I had a question, I would email Garmin and submit a form at https://support.garmin.com/support/sw/escalateForm, and a rep would ALWAYS get back to me by the next day. I asked them about the difference between heart rate monitoring between non-ACTIVITY MODE and ACTIVITY MODE (That's how I found out how to use it properly), what the screen is made out of, and other things, and each time a rep emailed me back with a full explanation (They actually READ each part of your email and answer it). :)

Other notable features:
The notifications are great to see on your wrist - I like the simplicity of it, to be able to read what your phone just buzzed from, move bar makes me laugh and works well when it "yells" at me to move.

Battery Life:
Is impressive...usually last 4 days [that's all day + 4 ACTIVITY MODE workouts]. You charge it via USB cord - takes about an hour to fully charge so I don't even notice the battery life because I feel like it fully charges so fast that it doesn't even matter. I'll usually work out, and if I see the low battery icon, plug it in, make my smoothie and take a shower, in less than an hour it's fully charged.

There are so many more awesome things I could mention but I wanted to stick with exactly what I use it for and enjoy.