I REALLY wish I knew this yesterday. I got the Note 7 which came with the gear fit 2 watch with a pre-order through Best Buy. I already had the Samsung Gear S (the one with the nice curved screen, got so many compliments) and I sold it on OfferUp. Then I set up my new watch, the gear fit 2, and realize it doesn't have my favorite frickin feature, the ability to answer a call and speak into it (great for driving). Also I'm 27 and in good shape I don't care about all the fitness stuff like heart rate monitor, step counter etc. I just want to be able to take calls, read+respond to texts, and check the time.
After a few days now I can comfortably say for me the Gear S is a MUCH better Smartwatch than the gear fit 2. I just assumed the newer model would have all the same features, plus new ones. Guess I should have done my research.