I really don’t use much more than a quarter of the 10Gb that I have available to me. I’ve gone into my listening habits in more detail in the past, but essentially, I carry around one 1Gb playlist, and occasionally toss one or two other specialized playlists on when I’m in a mood to, and that’s it. Right now, I’m currently using a whopping 2.12Gb of my 10Gb iPod for music, leaving around 7Gb free.
I have been thinking that I may never fill mine up . . . . I think 4-5 Gb is plenty, but that doesn’t mean I think it should sell for $50 less that the one I have.