Amazon Music Windows app has problems with exclusive mode to USB DAC. I still get the sampling rate set in Windows for shared mode, sampling rate in display doesn't change for HD or Ultra HD music, should switch in display on DAC if it's true exclusive mode. Also, setting exclusive mode for one output device in Amazon app in Windows doesn't save. It has be done every time. And there is no Chromecast support in Windows app, only on Android app.
Amazon has only popular albums sorting for discography for one artist, not by release date. Also saving an artist doesn't bring you to their page with all releases, just shows you what you have saved with this artist. Tidal is better on this.
Spotify has an awful GUI on Windows app, full of suggestions, sharing sessions, and it changes almost with every update. The search is full of user generated playlists, and is often not helpful. Spotify has also the very very annoying woman saying "Spotify is used on another device" seemingly with no reason. Also doesn't find Chromecast units regularly. One of their worst changes was to remove the individual setting for streaming quality for Wifi and mobile connection, but this they luckily brought back now.