Walt Mossberg reviews the new music services/clients from Amazon and Google
Google has a few nice features—it has a clever instant playlist creator, and, when uploading, it tries to prioritize your most played songs. But, overall, I preferred the Amazon player, mainly because it gives you much more control over exactly what you want to upload or download, down to the individual song. Google will upload only large collections, such as your iTunes library or main music folder. If you want to upload only certain songs, you have to create a folder containing only those songs. If you want to download only certain songs on your Android device, you must first make a playlist of those songs.
Also, the Amazon service found all my iTunes playlists, but the Google service omitted some. In addition, Amazon sells digital music and can deliver it right to your Cloud Player. Google doesn’t sell music. Neither service will upload or play back copy-protected music.