I have one and I have to disagree with what you say about the battery life. I have used the watch for over 2 days and it's still on 85%. I have the display configured to turn on when I raise my wrist but I have been using it to read notifications. Previously I had the LG Urbane and I was worried after reading reports about the battery life that I might need to charge the Gear s3 more but that's not the case.
I love this watch, the quality of build is fantastic. App support could be better but you know for a watch the apps that come standard do just fine.
So I use my Gear S3 as a standalone device (yes with out a cell phone connection) & it works fine. I don't get the 2 day use without a charge like I've read & heard. Neither have I personally gone a night without sleep, I charge my Gear each night. I purchased Bluetooth neckwear to talk privately with calls, however the building I work in has Very Poor reception. So my Gear S3 will Constantly search for a data connection. PLESASE BE AWARE!, this Will Drain your battery in less than 5 hours! I found out the hard way. So Yes This Sucks! I place my watch on Greyscale until I leave my building, ie: going out to my car, or walking the campus for some reason. If I had know this, I would Never have purchased this devise. Never. I cycle & I love S Health. To sum up, I love this devise except when at work. Long story short I will be tethering this bad boy to my cell via Bluetooth as recommended.