Wow! love the watch, it tracks calories, sleep and everything the fitbit device has, better than most. Smart features of this watch are accurate, like you expect from Lenovo. Sleep Tracking and calorie counter are almost exact, there is sometimes a little difference in heart rate monitor but the difference I measured was negligible.
The watch is durable and light weight, unlike heavy big dial smart watches, this is a better deal. It keeps you healthy! It is comfortable enough to wear while you are asleep. I have tried the Chinese MI version of the device, it is better than that. It was easy to connect with my android and even connects with the Iphone(I checked it). No compatibility issues with Samsung, MI or Apple. I think would work with most devices.
It looks good, so it is not like you would be embarrassed to go out with a kid's cheap digital watch like many smart watches. It doesn't look very formal bit not too ugly that you have to avoid wearing it outside the house. Has a decent look, reasonable for a smart watch of this category.