HR Function is not accurate
347438
Im a huge Garmin fan but this one isn't for me.  I purchased it for the HR function and it is not accurate.  I had a side by side comparison that proved it wasn't functioning properly I wish I hadn't tossed the box out because I would love to return it.
4848194
The strap syncs with modern treadmills and stationary bikes.
Seems fairly accurate.
Doesn't have Bluetooth, but those are 50+ dollars. (which is ridiculous, considering Bluetooth chips cost 1-2 dollars bulk)

The watch is simply not reliable.
It often gives me readings of well over 200 bpm when I'm not even going all out. (I know for a fact my max HR is under 190)
For example, at one point the treadmill said 176, the watch 216!
1681509
In its first 6 uses, the Sensor/Watch (not sure which is ultimately having the errors) malfunctioned during 2 workouts. The second time I used it, it recorded my highest heart rate as 212bpm. I just used it again (workout #6) and it recorded my highest heart rate as 116% of my HRmax. While I wish this was correct (because then I'd be a X-men), clearly something is wrong with the product as that's physically impossible. I just called Amazon to initiate a return. Hopefully there's something out there that's more accurate for the same cost.

When the HRM worked correctly, one aspect that I didn't like is that anything under the "pointer" is considered "fat burning." At the beginning of my warm up, when I haven't moved yet and my HR is in the 80's, the watch logs that activity as in the "Fat Burning" Zone.  Remind me to record a workout while I take a nap so that can be logged as "Fat burning"!
4643537
Not very accurate. I first purchased it primarily for heartrate monitoring. While I'm at the gym on the eliptical the display says my heart rate is ~103 the eliptical says it's 132. So i get off and count beats for a minute just to see and I counted 128. It's off by almost 30 bpm.

The other aspect I wanted to try was the sleep monitoring. The first few days I'm looking at it in the morning and it seems to round up the time. Let's say iI look at 625 am when Ii wake up. It says I slept till 630am. So I am looking at it in my sleep ok. Not a huge deal. One night I'm up working late and get to bed at 1220am. Just after midnight. It says I was asleep at 1130pm. The time is retrieved from the device it's paired with and my phone isn't an hour off. How can I trust the readings it gives me while asleep when it doesn't know if I'm awake or not?

Lastly it is water proof, but I can't get the screen to stay illuminated long enough while swimming to even get a heart rate reading. I'm not sure whether or not that's supported because the instructions for it are short and extremely vague. I made the purchase while trying to be thrifty...You get what you pay for. Guess I will just have to invest in a fitbit.
2269997
I wanted a device that pretty much does it all and is accurate. I used to upgrade Fitbit products, but found their accuracy was way off. I mean, who am I kidding when I get steps counted for clapping my hands?

I owned the Garmin Vivosmart and was pleased with that tracker. I upgraded to the Vivosmart HR when they were first released and, with the exception of the stairs climbed metric, and very pleased with its functionality and accuracy. Is the HR measurement perfect? Not at all, and you probably won't find any wrist worn HR tracker that is as accurate as a chest strap HR monitor.

This device has many more plusses than negatives, IMO.
+Clearly readable screen that lights up with the time, date and day of week
+Move alerts
+Alarm function with vibrating alert
+Fairly accurate HR
+Text/phone/email notifications
+Weather
+Distance traveled
+Calories burned
+Active minutes reading
+Steps
+Sleep tracker
+Ability to track runs, cardio or other activity separately
+Ability to switch to portrait or landscape viewing modes
+Waterproof. Can be worn while swimming or in the shower
+Slim profile. Not bulky or obtrusive

-Stairs climbed is way off. Per Garmin tech support, they are aware of this issue and are working on a fix
559514
Most functions stopped working correctly in six months. Heart monitor is not accurate, counts about 60% of steps and on a track a lap will vary from 1/10 mile (actual distance) to 1/20 of a mile. Must be something better out there.
3056571
I bought this at Christmas time, and was super excited to not have to use a chest strap (which chaffe terribly- post run showers are torture!). I want to like this so much that I keep trying it, when I should have returned it months ago.  After reading the reviews, I am curious why some people find it to be extremely accurate and others (like me) find it to be very inaccurate.  I've compared it to my chest strap, I've stopped running and counted my pulse manually, and Ive tried it in every position possible on my arm. Any suggestions?  It will jump from 90 to 190 within minutes of running at the same pace.  Sometimes I'll power up a hill (knowing my HR is about 170) and it will read 100, other times I will be running slowly on a flat trail (perceived HR around 130-140) and it will show 170.  I also tried the TomTom cardio and didn't find that accurate, so maybe it's me?  Any thoughts or suggestions?
1103769
I returned it because it did not keep an accurate reading on step activity.
121123
I belong to any 24 Hour Fitness Super Sport, Sport, Ultra, and Active. I generally attend five different gyms throughout the week. The Downey, Whittier, La Habra and Puente Hills gyms all have the Precor recumbent bikes so I have access to dozens of them. All of them are new as the gyms just got them. Not one of them is calibrated correctly. If the heart rate monitor works they are usually way off. Today my maximum heart rate measured at 108, yesterday on another machine it didn't register at all. Enough said about "POLAR TECHNOLOGY." For my 60 minute intense workout it tells me I burn 10.5 to 12.5 calories per minute for the same intensity. Nothing is accurate with these machines and they are new. Remember I have access to dozens of them so it's not like I tested a lemon. They are all lemons poorly designed and unreliable. Since the Precor does not respond properly I currently wear a Fitbit for heart and calorie monitoring.
4407223
I bought this to pair with my vivofit a product I love. I've used a timex ironman with a monitor for years and finally decided to replace it with this setup. After 3 months I'm still using my 4 year old timex.  To start  the monitor does not read my pulse accurately and it often looses connection from the vivofit so of the times I used it for running, I'd finish a 45 minute run to see that it only recorded 15 minutes of it. Also of the time it did record, as my heart rate increased it was showing my rate dropping to about 40 beats a minute. ( in reality my rate is about 140 beats per minute when it shows 40).  I'm experienced with heart rate monitors  and I know many tricks to improve connection and none of them have worked.  I contacted garmin and they sent a replacement unit. And it has been exactly the same.
  Now for the customer service..... I had to email then wait a week for a response. I replied to the email they sent me answering some questions, and ,waited another  week for an answer to find it answered by a different person.  They sent me the replacement that I had to wait 3 weeks for  and when it didn't work, I emailed and had to wait a week yet again for a response. This time the response was a list of ways to try to make it work INCLUDING TRY WEARING IT BACKWARDS OR TURN IT TO THE SIDE.  I'm pretty offended by this because I feel like you should be able to wear something as it is designed and as it is supposed to work and have it just work.  I emailed a response to that and had to wait again a week for a response.  They implied the last time that I must not know what I'm doing and have not responded to any more of my emails.  I was planning on getting a gps watch but now I will be researching the newest timex run trainer 2.0 or the new tom tom runner gps.  I WILL NOT WASTE MONEY ON Garmin again
3210351
I've had the device for a little over a month, so I feel this is fair.  The device itself is fine - rubber strap that is easy to clasp, kind of cool display that is easy to navigate - but it has some flaws.  First, I question the accuracy of the heart-rate monitor.  I've been using it during my workouts for the last month, and the results just aren't making sense.  I use a norditrack, and I started out today using the leg and arm motion.  my pulse started at 86 and sent down to 68 after five minutes.  there is just no way that happened.  The software is also very poor.  it is flakey and sometimes won't synch with the device.

I can't recommend this product after my experience.  I want a device that can track heart rate during a workout, and I don't think this is the one.

Update:  August 2017
I finally gave up on this thing.  In addition to the wildly inaccurate heart rate monitor, the device stopped synching with my phone.  I contacted tech support, they said it was a known issue, and they asked me to provide details to them so they could identify and correct the problem.  Given the cost of this device, I think they should provide a solution, not ask for help finding one.
482013
This fitness tracker has a lot going for it. It tracks sleep, steps, heart rate, calories burned  and distance. Unfortunately it doesn't do any of them very accurately. At least for my unit. Yesterday I started out I walked 3 1/2 miles on the treadmill. Fitness tracker showed I did 6200 steps and my iPhone app showed 7600 steps. Since I walk daily about 3 to 4 miles I know that the 7600 figure is accurate. I spent the rest of the day working around the house. I had to move my office from one end of the house to the other. Since I'm self-employed and work at home there was a lot of stuff to move. At the end of the day my iPhone had me walking 12,900 steps the fitness tracker showed 6800.  This morning I had the band on and I had my phone with me most of the time, although I did walk away from it three or four times. At one point I checked the steps and my iPhone showed 909, the fitness band showed 129. I don't know if it tracks my sleep because it doesn't record anything. In the morning I sync it with the app and it shows 100% but there's no data shown in the app. it doesn't show steps or sleeping pattern. Maybe wrong with my unit. I don't know but it's going back.  Now I'm once again on the hunt for a replacement tracker.
1484837
Hi!
We bought this HRM to get more accurate reading. Unfortunately, this HRM does not connect with the app on my wife's Galaxy Note 4 even though it was paired successfully. Also, the instructions are not clear on how much moist should we make the rear of the belt. Fit is not comfortable either.

Will return it and buy a wrist HRM.
3646619
Unit does not keep an accurate constant beat.

It varies up to +-10%.

This is realy no great problem for me; because I purchsed

it for walking/running exercise pace.
607986
I'm not really sure how to review this - for the most part, I really like this watch. But I'm still returning it, for the simple reason that it doesn't count steps anywhere close to accurately.  I did numerous tests over multiple days where I walked 50 or 100 steps, counting as I went, then check my Steel HR. It typically only got about 50-60% of my steps. I wore both my Fitbit and Steel HR for an entire day to compare. The Steel HR had fewer than 50% of the steps of the Fitbit. I contacted Withings support, and they were very responsive, but they ultimately said they ran diagnostics on my watch and everything checked out fine, so they couldn't replace it.
Maybe it's just something about how I walk, I don't know. I would have liked to try another one to validate that the first one wasn't defective.
It's unfortunate, because I do really like this watch otherwise. It's the only watch I found that checked every box for me - love that it's waterproof, great battery life, has the notifications I wanted, tracks heart rate, and actually looks great.  But not counting steps accurately is a deal-breaker for me. I'd buy again in a heart beat if I knew it would count my steps accurately.
2907976
If you want an accurate timer this is not it.
4606945
Very disappointed in this product.  On paper it was exactly what we wanted but the reality is that it is not accurate.  For a month I have been comparing it to several of my older traditional thermometers as well as an online weather site.  It was off anywhere from three to eight degrees.  If it was off at the same  rate consistently, I could live with that, but it bounced around so much, I never knew what was going on.  It also needed to be rebooted at least three times in the month we owned it.  The worse part is that I wrote to the company directly and basically they told me the discrepancy was within their company standards.....what???  Every time I looked at it, I would get frustrated and annoyed so  I finally gave up and put the thermometer away.  Out of site and out of mind.  There has to be a better product out there...just not sure if I have the patience to try another one.