I have a a 30gb IAudio X5. If there's one reason to get it, it's the sound quality and the build quality. The sound from the oe earphones is fantastic. I can't imagine what it'd be like with some good ones. The case is all aluminum and just feels solid. Check out:
http://www.iaudiophile.net/forums/forumdisplay.php?f=28

It's a good place to find out more about it.