Requirement number two mattered because I care about the audio quality, and I made some effort to generate good sound files. I initially ripped my music to lossless FLAC format, and then transcoded to VBR 224KB MP3. That's what I wanted to use on the player.

When I focused my research on sound quality, I was surprised to find out that Cowon, a company I'd not heard before, was frequently mentioned. The iAudio X5 seems to have gathered quite a following.

I chose the basic X5, a 30GB disk based player. There are versions with larger disk and larger battery.

When I plugged it into my Linux system, it recognized the device immediately and mounted it as a VFAT filesystem. All I had to do was copy my music into the Music folder.

The iAudio does something that is either very good or very bad, depending on how your music is organized. The player has no database or search tool to find music. However you choose to organize your music files on disk is how it presents them to you. Its music navigator is a filesystem browser.

I have all of my songs organized and sorted by artist and album, so this is totally awesome for me. If you don't have your music well organized, then you'd hate this player.

Another really nice thing about this player is that it supports OGG and FLAC music formats. I believe the manufacturer has a version of the firmware you can flash to support DRM formats. There is also video capability (MPEG4 format, I believe), but I haven't tested that.

As far as the sound quality, I was reasonably impressed. I'm using a pair of Sennheiser PX 100 headphones for listening. They are good sounding inexpensive phones. One of the first things I put on was Rhapsody in Blue, and the quality was rather striking.

So, if you are ready to move beyond the iPod to a more sophisticated choice, I can recommend the Cowon iAudio X5 music player.