I've had a smart watch before, and quite frankly, it wasn't all that smart. Constantly annoying me with irrelevant information.
Having owned iPhones for years now, when the first Apple watch came out I was definitely intrigued. Then the second generation came out with more features and I paid closer attention. Well now that the Series 3 is out with GPS (the version I purchased) I couldn't be happier.
It's a nice slick interface, just like you are used to with Apple. The watch faces are clear, and interesting, and incredibly customizable. I like the fact that it tracks indicators of heartbeat, distances, flights of stairs etc, without you even having to do anything to the watch. It's just doing it all in the background, so it's not obtrusive.
You get reminders to breathe or stand up every now and again, but you can turn those off if necessary.
Connecting your phone to Apple CarPlay, the navigation also shows up on your watch, and it vibrates when you are coming up to your next intersection or direction change which is pretty neat.
Overall, I'm really happy with the watch, I mean it shows the time, just like you'd like a watch to, but it also shows notifications from my smart home, if cameras have been triggered etc (all via a connected phone) I didn't go with the cellar version.
Emails show up nicely on there, as do attachments and pictures.
A neat feature I didn't know the watches incorporated is the ability to talk and hear phone calls through it, very 'Star Trek'!
Only consideration I have is to not club the watch off of walls or desks etc, being as it's an expensive piece of kit!