First of all, I will recommend this smart wristband, Garmin Vivosmart, to other people.

Then, bad things first.
Cons:
1) Don’t include the complete user’s manual within the packaging. It does come with a “quick start”. But that brief “instructions” do not tell you about all the features of Vivosmart. To save your time, the link is http://static.garmincdn.com/pumac/vivosmart_OM_EN.pdf
2) Don’t support non-Latin characters, such as Chinese. On the wristband, it will just skip non-Latin characters. (Note: skip, not replace them with squares or spaces) But it’s fine. I didn’t expect to check messages from this small band. As a reminder of what’s going on, it should be enough.
3) The companion app on the phone needs more work.
4) Price could be lower. 🙂

Now, it comes the good things.
Pros:
1) Notifications! It’s the number one reason I choose Vivosmart. I used to own a Fitbit Force, which was guaranteed with a “coming soon” notification function that never came before the bands were recalled. I paired it with my iPhone 5s. The notification feature works perfectly so far. And thus, I have to turn off notification for some unused apps in order not to be annoyed.
2) Waterproof! It has a waterproof rate of 5 ATM. It means that you can definitely swim with the Vivosmart on. But please make sure that you attach the black clasp, which is included, in order to secure your band from falling off. If you swim in salted (sea) water, don’t forget to clean the band with clean water afterwards.
3) Anti-lost/find-my-phone function! You can use the wrist band to find your phone when they are still connected through Bluetooth. Vivosmart will make your phone play a sound even in silent mode while you are trying to find it. The display on the wristband also indicates the distance between the band and the phone. Otherwise, the band vibrates when lost connection with the phone. You should be alerted if your phone is stolen at this time.
4) Time display and alarm clock. This actually comes handy. You can also modify the settings to let it light up and display time when you raise your hand. But currently, you can only set one alarm clock on Vivosmart.
5) It’s light and low-profile. Its appearance is way better than the dis-continued Fitbit Force (personal taste matters).
6) Health-related things. The band counts basic parameters, steps, miles, and calories, as other health wristbands do. But it also has a “Move bar” which reminds you to stand and move around if you sit still for more than a hour. By the way, you can also track your sleep using the band. In order to track heart rate and cycling workout, you will need to buy extra monitors to pair the Vivosmart wristband. Since I don’t have these extra accessories, I have no idea how they would work together.
7) 7-day battery life. It’s just reasonable.
8) Music control. I don’t use this function though this could be handy to other people. I control the music playing on my phone using my bluetooth earplugs.
9) Garmin Virb camera control. I don’t have a Virb camera. So… Never mind.

I’ve been using it for about three days. I know it’s not a long time. I still need another four days before charging it for the first time. I will update the review if I find out anything else.

I have used virtually every fitness band since the original Jawbone UP disaster. (UP, Nike, Polar, FitBit, Shine, etc.)
I have also tried the Pebble Steel smart watch. But a smart watch is a notification / control device first and a health device second. Plus battery life typically is no more than 1 day.
All of the monitors had strengths and weaknesses.
I am not a fitness fanatic, but I am a senior citizen who is of necessity health conscious.
Of the simple devices I liked the UP24, but the way the bracelet fit was a problem for me. I was constantly catching it on clothing etc. But their ecosystem was the best I have seen to date.
Of all the fitness monitors with display, I have best liked the Polar Loop, the Garmin Vivofit and now the Vivosmart. I prefer those three because they can pair with a heart rate monitor for those times where I am at the gym and need to stay in a particular HR zone.
The Polar loop was excellent BUT the touch display required a solid connection to your wrist before a finger touch was detected. Plus when you are in motion you have to use both hands to see the display.
The Garmin Vivofit was near perfect for me. I loved the battery life and the always on display. I didn’t like not being able to tell the time at night.
The Vivosmart is the best of the lot for MY use. Water PROOF. Reasonable battery life, it turns on with a raise of my wrist, it has all the fitness features I need (including heart rate) AND it has a moderate number of alert capabilities.
I have carefully tuned my iPhone to only include certain types of alerts in the notification center. For example email only from those in my VIP group. That keeps the number of alerts on my wrist to a minimum.
My only issue is with the Garmin Connect service. In general it lags behind FitBit etc. Sleep data is captured but not analyzed. Food can be logged into Myfitnesspal but there isn’t (yet) much of an exchange of data beyond that. ETC.
My needs are well served by the Vivosmart. I have no need for an Apple Watch or a Motorola 360. The wrist based HR monitor devices are all either flaky during aggressive exercise or not water resistant enough for the shower.
I suspect I will keep wearing the Vivosmart for some time to come.
YMMV.

I got one early from the brick & mortar store that has a temporary exclusive on Vivosmart. HIGHLY recommended. I’ve had a couple of Smart Watches (the original Sony SmartWatch, the Pebble) and I’ve had a Jawbone UP (previous model, no Bluetooth). This is every bit as comfortable as the UP. The heart monitor that’s bundled is the best bit one I’ve ever seen, way better (and more comfortable) than an older Polar one I had. I would say the biggest negative on this band is the 7 day battery life, versus the new UP’s 14 day, but plugging it in once a week is not that bad, honestly, and is in line with my Pebble, and the original UP band.

Now for the Pros.

1) Compatible with ANT+ bike sensors (speed only, not cadence, hopefully cadence will be an upgrade). Fitness bands tend to be for all activities except biking, so this is a huge plus.

2) Garmin Connect. If that’s not your preferred site, it may not be a plus, but for me, it is. I already have a Garmin GPS for my Bike. Having all my other data on one portal is a plus for me.

3) Water proof. Wear it swimming or in the shower. Big plus, especially if you have triathlon aspirations. 🙂

4) OLED touch screen. When in range of your smart phone, displays notifications (Android or iPhone, Bluetooth 4 required). Love it. See who is calling, text messages, app notifications, etc. When your smart phone isn’t in range, it still tracks your activity.

The Cons:

1) Wish the bike sensor support worked with cadence, not just speed. Hopeful for an update.

2) Battery life on the low side compared to other bands. But again, if you want some "smart watch" type functionality, this is a good trade off for me.

Why not a smart watch?

Too many trade offs. 1) Price 2) They scratch 3) requires charging every day 4) not designed for fitness 5) no bike compatibility 6) many aren’t water proof

This is comfortable enough to sleep in (important for sleep tracking), lasts a week on battery, works with all my exercise types, and continues to work 100% when my phone isn’t around (except phone notifications of course). You can even sync it to a laptop and never connect to a phone if you were so inclined. Being compatible with ANT+ (and shipping optionally with a great heart monitoring band) is a plus, and the rudimentary cycling support is a step up from the competition.