I know you're really into fitness, why won't you go Garmin?
I had the Garmin Viviosport for a bit (and a Fitbit). It was okay but the app was lacking for me. Healthkit & the health app in general have been super motivating for me. The simplicity of having only the metrics I care about in the front of the app, while still having access to the insane amount of metrics was a game changer. Add in the monthly challenges the watch throws at me and I'm hooked.
I have the display on my AW set to show my rings and that gives me daily motivation to get off my ass throughout to close my stand rings, ensure I won't skip a workout each day to close the exercise ring, and lastly to ensure that workout is enough to close the goal I set on my activity ring. It is dumbed down in a way that makes the game of closing the rings engaging. And if I want complexity, it's available to me.
I also love the integration into my calorie tracker app (MyFitnessPal). If I work out hard enough, it takes those calories and gives them back to me all done seamlessly without my intervention. I can even track my protein intake (or any other metric) over long periods.
Once Fitness+ launched, I was further enamored with the capabilities of the watch. I've never paid for a fitness subscription but this is one I have no regrets about.
Add in that the watch does so much more and for me, it is the perfect device.
The Apple Watch was the one thing that made fitness a lifestyle, rather than a hobby. I know it won't work for everyone but it really has been the catalyst for long-term change for me. I 100% would recommend to anyone who has felt lackluster about fitness trackers. But do know that if you don't have the drive to get into activities, there is no guarantee the watch will magically give you desire. It's an aid not a solution.
I am more interested in what Apple has in store in general in the wellness/fitness space than any other. I would easily choose the watch as my favorite device I've owned.