The Shuffle works seamlessly with the latest iTunes 4.7.1, which includes the mentioned autofill feature that automatically loads the Shuffle player with an optimal number of songs based on user preference. Our first 512MB autofill stats: 488MB, 103 songs, 7.5 hours. We're wondering why iTunes wasn't able to cram another 4MB-plus of audio (the amount of space left for audio data) onto the Shuffle. For those who will use the Shuffle as a storage device, iTunes will allocate a specific amount of space for dedicated data storage. You can direct iTunes to swap out the Shuffle with brand-new songs and/or load them randomly from the playlist of your choice, as well as manually transfer the songs yourself. And remember, if you're an iTunes Music Store junkie, the Shuffle is the only flash-based player that will play your FairPlay-protected AAC files.
Speaking of supported file formats, the Shuffle will play back AAC up to 320Kbps, MP3 up to 320Kbps, MP3 VBR, WAV, and Audible files. It does not support AIFF, Apple Lossless, and of course, WMA.
Die-hard Shuffle fans will appreciate Apple's nice set of accessories, each costing $29 apiece. These include an AAA battery pack, a miniature dock, a USB power adapter, an armband, and a cool protective carrying case. More will surely come from third-party vendors.We were able to get 15 hours out of the Shuffle, which is considerably less than some other flash-based players out there, such as the 40-hour iRiver iFP-800 series but plenty more than Apple's claims of 12 hours. But realize that most other players lasting more than 20 hours typically use a replaceable battery--good for convenience, though bad for the wallet. The Shuffle takes two hours to charge to 80 percent and a full four hours to charge completely. If you're traveling with it, you'll need to have a computer or the optional power adapter (which is several times larger than the Shuffle itself) nearby. Transfer time was 1.4MB per second, noticeably slower than a hard drive-based iPod's and disappointing for a USB 2.0 device.