I have a Garmin Venue 3. I like it and would recommend it.
My main purpose of getting a smart phone was to have the ability to get quick notification of messages/emails coming in. I am not always near my phone so I wanted to know how urgent the call or message was and if I needed to act on it right away.
I did want it to have the ability to answer calls. I am often on a ladder with the phone not on me so this way I can answer the call if I really have to. I don't always use the feature but I know its there if I need it.
It does track things like heart rate, sleep score, stress level etc etc etc. All the smart watch things.
I don't necessarily use these functions on a regular basis but view my heart rate from time to time. More of a curiosity thing.
I don't sleep with it so I am not sure what more sleep score ever is. Probably in the negatives.
Battery is very good on it. Somewhere between 1-2 weeks before charging.
I think they just release the new verion of this, the Venue 4 at $769. Well
My only complaint is, and this is not the fault of Garmin. I use a snap on screen protector and I have noticed that the sensitivity is poor and doesn't always respond to a swipe. This for sure is due to the cheap and disposable screen protector. I am ok to live with it. I would rather change a $5 screen protector than damage a $600 watch.