I've tried several smartwatches, including the Gear S2 (which I thought was rather awful and barren in terms of functions), and eventually I finally settled on the Huawei Smartwatch. It depends on what you're looking to get out of it, but the Huawei is the most sleekly-designed watch I've found, and it's got a pretty good battery life (I can generally make it through two days without charging it, but I charge it while I sleep). If Samsung has drastically improved their shitty Tizen OS for the watch and made the watch able to use any Android Wear apps instead of only Samsung-approved ones, then I'm sure the S3 is great as well. I kinda prefer the stock Android Wear experience, though.
Tizen is the reason I'm considering a Samsung. I'm honestly just sick of Android at this point.
Well, if that's what you want, go for the S3. I personally think Tizen is far more awful than Android, but to each their own.
I think the most positive comment I've heard from one friend is that she no longer has to take her phone out of her pocket to look at text messages she receives.
Since I seem to be the only smartwatch user here, I'll chime in and say that's fair. My watch isn't really a standalone device so much as a complement to my phone. Though I'd extend it to more than just "checking texts"; I practically never take my phone out of my pocket except to take calls now (unless I'm at home and playing games on it). So viewing notifications, responding to them, searching things, checking time (obviously), checking weather, tracking fitness (which some people don't care about, but I like), taking notes and reminders, etc.
I tell a lot of customers at work that, yeah, if you're expecting some whole new paradigm of technology, you're in the wrong mindset. It's basically having your phone on your wrist. If that's not something you're interested in, you probably don't need nor want a smartwatch.