While you're not getting Spotify or Apple Music here, you are getting enough storage for 500 songs with a process that's fairly easy. You just boot up Garmin Express, select the Music tab and choose which of your own music you want to port over. If you do want to sync over playlists from a streaming service, your only options are iHeartRadio and Deezer.
For deeper integration with your Android phone, you can give Google's Wear OS platform a try with Fossil's $275 Q Control touchscreen smartwatch. It lacks GPS and support for NFC payments, which is why the Gear Sport is a better fitness-focused smartwatch for Android users, but Fossil's Google Assistant integration and stylish design make it a solid contender. However, smartwatches with Qualcomm's new Snapdragon Wear 3100 processor start shipping in October, so you may want to hold off until we put them to the test.