I think the technological "use-case" of the Apple Watch is still in flux. Its a nice item but not absolutely essential. "+" phone owners like not having to get the phone out as often but I think the killer features haven't surfaced yet. I have used one but do not own one. As a watch wearer, I like many aspects, but I feel like there is something that hasn't been discovered in a use-case scenario that will make this semi-essential.
I think the Apple Watch currently does three things:
1) it is a timepiece. Yes, I know that's painfully obvious, but Apple did make a big deal out of how accurate it can tell time. Plus, the emphasis on the materials of construction for the watch itself, plus the many watch band designs, show that Apple is trying to reach the "watch geek" who like to purchase and wear timepieces.
2) it is a health and fitness device. No surprise here with all the emphasis on this area, along with the rumored work Apple is doing for diabetes research, but this is probably the area that attracts the most interest from the general consumer.
3) it is the second (widget) screen that the iPhone doesn't have. Android apps have widgets and a way to customize the interface with widgets to personalize the phone the way you want. The iPhone doesn't do this, but the Apple Watch can be your second screen with small apps that
should be designed to complement, rather than compete or replace, the app on your phone. This is still an area of flux, as only some apps have done this right. (IMO, Apple is partly to blame for this for not clearly describing the ideal app for the watch.)
Also, you can find watches that pair with the iPhone that can do 1) and/or 2), but none can do all three except the Apple Watch, which makes it unique.
I have an original Apple Watch, and wear it every day, and as long as I hold it to these three expectations, it serves me very well.