As might be expected, the W-Series Walkman's interface is rather nontraditional, although it is quite simple to get music onto the device. You can drag-and-drop directly between folders using either Windows or Mac, and Sony includes its nice little Content Transfer app (Windows only) for transferring music from jukeboxes such as iTunes and Windows Media Player. Unsurprisingly, the W-Series Walkman is an audio-only device; it can play back MP3, AAC (unprotected only), and WMA (subscription included) files. Although a playlist section showed up under the player when we connected it to our PC, there is no indication by Sony that the device can support anything resembling a playlist. This would be a welcome feature, considering the sporty applications.
The W-Series Walkman is predictably light on extras, but Sony does integrate a few unique and useful features. The first is something called Zappin, which lets you browse through tracks by ear by playing a snippet of the chorus of each song. If you come across a song you want to hear, a press of the jog button will start it from the beginning. The player also offers a quick-charge feature that will give you 90 minutes of playback from a 3-minute charge--particularly handy for a fitness-friendly player. We appreciate it even more given the paltry 11 hour battery life, which is unimpressive for a Sony device but understandable given the size of the device. Also understandable is the lack of an integrated FM tuner, though it would have been a nice feature to have at the gym.
One of the issues with the previous W-Series Walkman was its inability to withstand sweat in real-world use, so Sony made an effort with the second generation device to improve the water resistance. We weren't able to work up enough of a sweat during testing, but we did run the unit under the tap for about a minute and it worked just fine after that, so we're confident the player can hold up in most moist situations. As for the straight-up digital-audio playback, overall audio quality will depend at least somewhat on how the headphones fit. The deeper the earbuds go and the better the seal, the deeper the bass response will be. For our part, we had to hold them in to really hear what the W-Series could offer on the low-end--and what it offers is more than adequate. Regardless of fit, you can expect clear-sounding audio with no distortion or background hiss. Also, the earbuds aren't the best at blocking outside noise, but this is a good thing if you're going to be jogging outdoors. The player's volume gets plenty loud, though, if you want to drown out the hum of gym equipment.