I have heard from a few people about it. Can't speak from my own experience but all of them have talked nothing but nice things about this smartwatch. As a matter of fact, they couldn't stop bragging about it
It is not even that pricey considering how good it is. $350 is not that much for a device of such a high quality. Only thing that might be considered a minus is that is pretty big and also really heavy for a watch.
It has everything you are looking for in a smartwatch and the battery is amazing. As far as i have heard it can last around 3 days with decent amount of usage.
The Samsung Gear S3 is a watch that went big in a bid to match the success of the Apple Watch 2 (And Subsequently the Apple Watch 3) - and it means literally. This is a huge timepiece that offers all the features you'd expect from a smartwatch, including GPS, a heart rate monitor, water resistance, NFC, activity tracking, an altimeter and in some cases even LTE. It pairs them with a great screen, a long-lasting battery and - similar to Apple - a high price, all wrapped up in either a sporty 'Frontier' finish or a smarter 'Classic' look.
One of the key selling point of Gear S3 is fact that it is compatible with the latest Samsung phones, but also with most other Android phones running version 4.4 of the OS or later, as long as they have at least 1.5GB of RAM.