I just got a couple of Node 2is, one for the living room and one for my listening room. It's my first foray into streaming other than Amazon HD on the phone for headphone listening and use in the car.
I like it so far, especially for the wife. I set the presets for her favorite playlists, and set her up so they show up on the Harmony remote touch screen with the playlist names. And the phone app is easy enough for her to use to play other stuff, as it's similar enough to the Amazon HD phone app that she didn't have much trouble with it. And she has severe challenges in dealing with new technology.
Could it be better? Sure. Most of the problem is that Amazon doesn't really have an API that I've found beyond the Alexa skill api, which kind of blocks third parties from developing a full featured Amazon implementation.