I dont own one, but i have used one.
I tried the 20gb version. To be honest, i was totally blown away!
The design is smooth and sleek, the interface and functions are excellent.
The one i tried was loaned to be by a member of a very famous world wide band.
He had 500meg free and had JUST UNDER 3000 songs on it!!!!!!!!!!!
YES I DID TYPE 3000!
The sound quality was excellent as was flicking through the songs, choosing from either Artist, Album or Genre
But it all boils down to how badly you want on, because the 20gb version costs nearly £500.
Of course they come in 5gb 10gb and 15gb aswell.