Tizen or Wear OS?
Most smartwatches run on Wear OS by Google. Samsung created it’s own Operating System for smartwatches: Tizen.
Other manufacturers have done the same: Garmin has its own OS, and Fitbit also for example.
Tizen is a lot more easy to use and navigate than Wear OS. It offers the most features out of the box. It does not have so many apps available as Wear OS smartwatches, but do you really want all of these apps anyway? We don’t think so. Most of the time you just grab your phone when you want to do something that your smartwatch alerts you about.
There are several kind of smartwatches: the best ones are the ones that focus on a specific task like the sport watches from Garmin, or the fitness watches from Fitbit or an outdoor watch like the Casio FS20/30. They help you with your activities first, and notification functionality and apps comes second.
The Gear S3 and Galaxy Watch are the kind of smartwatch that try to do it all. And our experience is, that it does this very well. Sport activity tracking is not at the level of Garmin or Fitbit, but for most people it will do fine. We found that heartrate monitoring is accurate, and that Tizen is a very stable OS that is far ahead of Wear OS. You do need to charge it every day, but this is the case with many smartwatches, except for the Garmin and Fitbit sport watches. The Galaxy Watch does a bit better here then the S3.
Our advice is: if you are very serious about sports (like triathlon athletes): go for a Garmin. If you want a smartwatch that first and foremost helps you monitor your health and assists you doing some light sport and fitness: go for a Fitbit. But if you just want a smartwatch that does as much as possible, is easy to use, and offers great value for money: then the Samsung Gear S3 and the Galaxy Watch are the best choices out there now.