I'll give one management schmuck's experience with my apple watch.
I got it about a year ago as a toy. Expecting nothing. However, somewhere around 4ish months ago when I went on a trip to south america without it, how much I missed it. And realized that dumb watches were just... dumb. For me.
Again, I'm a people leader in IT. My day is meetings, email, and texts. For that, having a glance and quick canned reply to texts and emails while I'm sitting in meetngs with VPs is a lot less disruptive than pulling out my phone. All fine and good. But that still just makes it a toy, right?
Well, not quite. It tells me where my next meeting is at a glance, right there on the face. It tells me how many to-dos I have for today, again right there. It tells me how I'm doing on my fitness goals.
It tracks my heart rate and exercise, which really came in handy when I discovered I have high blood pressure. I just handed my iphone to my doctor with the health app open. I've since got a blood pressure cuff that also syncs to health, and that really helps my cardiologist.
When I'm at home, I leave my iphone on my desk or wherever, and just go around the house or yard getting stuff done. When you're on wi-fi, it does a decent enough job pinging you with your texts and reminders... and even phone calls. Right there on your wrist, without your phone nearby, as long as you're in wi-fi range.
Something I've started doing is using it to wake me up it the morning instead of my alarm. A silent tap on the wrist that does't wake my wife up. I also use it to track my sleep habits, which I've found useful.
When I travel, I take it with me now. Switch the face to show the time at home, the local weather, and the local sunrise/sunset. If your airline has an app for it, it will alert you if your plane is delayed, or changes gates. I can even use it for some airlines as my boarding pass.
Apple pay works pretty good. I usually pull out my phone to do it, but when I'm in the self checkout line, it's easier just to put my wrist up to the device to pay.
At the end of the day, it's not an earth shattering device. But for me, it has become a pretty useful one, and I'd say I've gotten my $400 use out of it. It's tough now to go back to a watch that just tells the time.