Both Linux-based devices include a 40GB hard drive, a CD-RW drive, and USB ports (for connecting a portable MP3 player and, in the future, other devices such as a keyboard), as well as optical and RCA-jack audio outputs. And both offer listening options such as custom playlists and shuffled playback.
But the units do differ. The HP has built-in ethernet, a dial-up 56-kbps modem, and HomePNA support. The Rio has only dial-up and HomePNA support; you need a USB bridge to connect it to other types of networks. The HP has a four-line dot-matrix screen for on-unit navigation, but the device is optimized for use with a TV display. The Rio has a 4.5-by-3.5-inch, bright blue-and-white LCD screen, with no TV hookup required. Both rely on Gracenote's CDDB database for identifying album track and artist details, but the Rio has it preinstalled.
Highlighting the stylish HP De100c is its generally pleasing and logically designed on-screen menu. I examined a shipping unit. To access core functions, I just pressed the CD, Library, or Internet radio buttons to start. The included remote is similarly easy to use, and most of the De100c's functionality is duplicated on the unit's front-plate buttons.
In contrast, the preproduction Rio Central has a boxier design, which accommodates its larger screen. Many of its features are accessible solely via its cramped and difficult-to-use remote control. The on-screen navigation interface isn't particularly intuitive; to return to the screen you last viewed, for example, you have to retrace your steps from the top-level menu, instead of just pressing a Back button. I did like the large compass-like navigation pad on the front of the unit, however. Curiously, the unit lacks support for playing back MP3 CDs (you can rip MP3 files stored on a CD to the hard disk, but you can't play MP3 files directly from the CD itself), as well as direct ethernet support and Internet radio capability.
When I piped the devices' signals through my Nakamichi receiver to a set of Canton speakers, audio differences between the two were hard to pinpoint. I thought that the HP sounded fuller and more detailed. The Rio, however, had better noise reduction--the unit features some additional circuitry and higher-end sound output specs than the HP. My tests included a variety of music genres and used MP3s ripped at bit rates ranging from 128 kbps to 256 kbps (the highest rate that the HP De100c currently supports).
If you have money to spare, I would recommend the HP De100c for its ease of use and overall design. The Rio Central is a good first effort, and it deserves some extra points for its stand-alone functionality. But the Rio's interface and design drawbacks, coupled with its high price, seriously dimmed my enthusiasm. From the April 2002 issue of PC World magazine