Sony's Music Unlimited subscription service was already available on a wide variety of products like its TVs and Blu-Ray players, and now it's available on its line of Walkman PMPs. Similar to Spotify and Rdio, Music Unlimited allows you to stream anything from Sony's library of 10 million tracks, with the requisite playlist creation and genre-specific music channels, but moving that music to your Walkman isn't the most straightforward process. First, users must install the "Music Unlimited Transfer" application and plug their Walkman into a Windows PC. After that, you can transfer playlists or channels you've created over to the Walkman, but note that Sony's application doesn't actually let you create playlists or otherwise manage your music. It's only for syncing music; everything else is done through the web client.

The $9.99 / month "premium" plan lets you add anything from Sony's streaming library to your Walkman, but the $3.99 / month "basic" plan limits you to radio "channels" or music from your collection that you've added to your Music Unlimited cloud. While this may be a nice feature if you're fully ensconced in the Sony ecosystem, the notion of having to transfer music with a cord from an online streaming service feels rather antiquated compared to the major streaming services of the moment.