[Update 2/6/17: Don't know if Amazon Music just hit a eureka moment with my data, or the engineers at Amazon made improvements... but stations are noticeably improved in their variety and depth since I first wrote this post. I'm hearing new bands I've never heard before, and not a single Hardwired song hit in days. Good job, Amazon!]
I've been an adherent of Microsoft's music service (no, I never owned a Zune) pretty much from the earliest days of Zune Music on the PC. I've lived through the resulting brands - Xbox Music, and now Groove Music. I saw the birth and death of download song credits, the switch from WMA to MP3, and the embrace of mobile devices. Finally, in 2016, I gave up on the Microsoft music ecosystem.
It was a good service. It had most of the music I wanted to listen to for streaming, and built-in OneDrive coordination in their clients for anything they were missing. "Radio" for continuous streams seeded on a band name. Decent clients for all the major platforms.
There was really only one problem, that I couldn't get over: too often, I would press "Play" and music wouldn't start. Network issue? Backend congestion? Client bugs? OS faults? Who knows. Probably a combination of these over the years. But it's a fatal issue. This is a clear "bullshit test" - the basic proof of the most important base scenario in a system. It should never fail.
Should I blame Groove? Yes! Because another app has a great bullshit test - Netflix. When I push play on Netflix, video shows up. Every time, on every device, consistently fast. Streaming video is indisputably a much harder problem. If Netflix can stream video, Groove music should be child's play in comparison.
So when Amazon released their unlimited streaming family plan, I jumped on the opportunity. For $5 more a month than Groove, my entire family could jump on the service? Sold! Microsoft never offered a family plan (and we all asked... a lot!). Maybe this service would work better.
A few months in.... how do I feel?
Eh. Not bad. A bit better than Groove.
Amazon Music does everything it needs to. Clients on major platforms - notably a Win32 client, and an Android app. A collection to stream that seems (at least in the metal world) to be even richer than Groove. "Stations" to keep a constant stream of music going. An affordable family plan!
Most importantly, it works! I can play music quite reliably. I can make playlists. Download music to my devices. My most important feature - I can start a station and have music play all day while I work and/or travel.
But it's not perfect.
The clients are not yet mature. I like the clients. They look and feel nice for the most part. However, it's still pretty easy to find bugs in main flows (eg. adding music to collection). I also expect navigation will change as they discover how their apps are used. Finally - yes, occasionally I won't get music when I expect to. But it's rare, and more importantly it's recoverable. The client knows its having trouble, indicates it clearly, and lets you retry as needed.
Stations are not very creative yet. Unlike Groove, there is only a subset of artists for which you can start a station, and there's no good way to predict which artists will be covered. Once you choose a station, the song selection is appropriate but bland much like a physical radio station. A "greatest hits" feel - you'll like what you hear, but probably never hear anything new.
Stations are obsessed with Metallica. Specifically "Hardwired... to Self-Destruct". Sure, this album is popular, but EVERY rock station I generate will disproportionately select songs from this particular album. Never once any other Metallica album. Nor have I seen this treatment with any other album. This seems to be immune to the Thumbs Down. This is so pervasive in the rock genre, that I cannot possibly believe it's an accident.
No social. I have a family plan. Put my family's playlists somewhere, for those rare cases where I let my daughter choose the music in the car.