I think the Watch OS2 preview makes nightstand mode sound appealing:
https://www.apple.com/watchos-2-preview/
"Now you can use your watch even when you’re done wearing it for the day. Just place it on its side and connect the charger. Apple Watch will automatically go into Nightstand mode, a digital display that illuminates whenever you touch the screen, the Digital Crown, or the side button. Nightstand mode even changes how the watch buttons function. When an alarm sounds, you press the side button to turn it off, or the Digital Crown to snooze."
I have been using my iPhone as an alarm for years, but the watch would be less cumbersome to me. I charge my watch on my nightstand, so it would be very convenient to simply touch the screen or snooze/dismiss the alarm with the crown or side button. I charge my iPhone on my nightstand as well, but I fumble with it to turn off the alarm in my barely awake state. I think the watch will be the better alarm option. I also wear a Fitbit to bed for sleep tracking, and it has a vibrating silent alarm function that I use. I still use my iPhone though, because the Fitbit sometimes falls off at night or doesn't wake me up.
Some think nightstand mode is pointless if the display doesn't stay on all night, but I don't like digital clocks, displays or lights of any kind that stay on all night. I like total uninterrupted darkness for sleeping. It will work like the analog alarm clock I used to have that had a small light that would turn on, illuminating the face, when you held down a button on the top. The watch will be even easier since I will just need to touch the face or one of the buttons. No... it's not a killer new feature that will sell more watches. It's just another little convenience (that actually should have been there from the start) to add to all of the other little conveniences that make the Apple Watch so useful to me.
Sean