I have an Apple Watch and while it integrates well with the iPhone, I don't think it's particularly motivational on the fitness stats side of things. I actually miss my Fitbit with better sleep and active zone tracking.
Well, I came across the Garmin as my wife was on the hunt for a proper activity watch to give her some feedback on her running, swimming and general activity. She'd been using a 7 or so year old fitbit we had sitting around to see if she liked the idea before that, but the battery was pretty cooked and it was a really basic thing (just steps really).
One thing that has become very apparenty though is that Fitbit walks all over Garmin in the motivational / interaction thing. Garmin definitely has the hardware side, but just doesn't hold a candle to how she was using the fitbit, which is dissapointing. Just the notifications of getting sleep right, feedback on additional background activity, the way the app displays and so on seem to just work a lot better for her.
I tend to use Strava instead of the Garmin app, but did try just using Garmin for 6 months or so when Strava did it's whole 'premium for segments' only thing. It's just not the same, there's definitely something missing there on the interaction side. All the data is there, but just not as engaging. I ended up back on Strava and find it much more motivating.
So if you're looking at Garmin to fix the motiviational side of things, I'd look elsewhere, unless you plan to tie it in with something else.