I chose Amazon Music Unlimited. I'd been with Spotify most of the time since Microsoft closed down its Zune/successors service. I chose Amazon for three reasons: Spotify political/business choices (Bing for "Spotify controversy") I'm one of millions (?) who've opted out; cost savings -mostly explained by the lower cost of Amazon Music as a prime member, -so that I am leveraging my Prime membership investment, plus that Spotify has never offered an annual subscription cost savings; and finally, the improved Amazon service which no longer charges extra for high-res streams and has seriously improved and increased its hi-res offerings since I started exploring Amazon seriously last year. Spotify algorithms are/may still be superior on multiple counts, but, remarkably, it still does not offer hi-res streams, and eventually/soon, I probably would have changed for this reason alone.
One important factor that had kept me with Spotify was a desktop Spotify Connect device: I miss that option, but it's the only thing I truly miss.