I've got a 4G 20g (personalised!)
I visit a forum
www.ipodlounge.com (mods feel free to remove!) for hints tips etc.
I think the biggest downside is not being able to sort music correctly, I.e. by a different ID3 tag other than title, so if you want to listen to specific artist but what to play it by album in track order you have to amend the tags to be artist - album - track - songname