The MPIO One's onscreen interface is bright and cheery, with colorful animated graphics marking the different areas. We wish it were easier to navigate, though. We'd prefer a hierarchical menu, like the iPod has, where the menus relate in a simple, structured way. Instead, the MPIO One asks you to press and hold the Function button to jump to a list of different areas or press and hold the control stick to access settings. We were often frustrated with not being able to get to the right section because we couldn't remember which button to press. The music-playback screen is orderly but too crowded with information. How could it not be at that size?
The MPIO One's top holds a proprietary USB port, which connects with the included USB 2.0 cable. The player charges only through the USB connection from an active computer, so it's inconvenient for travelers. Plus, if you lose the cable, you can't simply substitute any other USB cable. The top also holds the microphone/line-in and headphone ports. The bottom has a hold switch and a reset button.
Weighing only 1.2 ounces and measuring just 1.2 by 2.2 by 0.5 inches, the MPIO One is so light and small that you'll forget you're carrying it. We like that it comes with a belt clip and a neck lanyard, so you don't need to purchase extra accessories to carry it easily.The MPIO One is at its best a music player, since it can handle MP3, WMA, WMA DRM (though not subscriptions), and OGG files, and it works with both Windows and Macintosh PCs. Windows users can load it from Windows Media Player, but we found it easier to simply drag and drop tracks. You can dump your songs into the Music folder or create subfolders to better organize them.
As a video player, the MPIO One leaves more to be desired, namely a larger screen. Even the Cowon iAudio U3's 1.3-inch screen looks big compared with the MPIO's 1.04-incher. The screen is more like a technical exercise--proving that the company can make such a small video device--than an attempt at creating something usable. We also find the box a little deceptive when it comes to video. It advertises MPEG-4, WMV, DivX, and AVI, but the MPIO plays only MPEG-4 videos. The other formats are convertible using the included Windows transcoder software. We had mixed results with the transcoder, as it handled some WMV and AVI files just fine, while choking on others for no apparent reason. Curiously, the transcoder also won't covert MPEG-4 files to the correct resolution. If you have an MPEG-4 file you'd like to load and it doesn't happen to have a 96x64-pixel resolution, you'll have to find another program to convert it. The player comes with Windows software only, so Macintosh users will need to find another way to downsize and convert their videos.
The MPIO One displays JPEG photos, and here, loading is easier, since you don't need to put them in any special resolution. They'll all display as indistinct smudges, with most detail lost, so being able to show them isn't much of a plus. Still, if we were looking at the MPIO One as purely an MP3 player, it is nice to have the extra photo and video features.