Younger daughter bought one, manages it with the Mac (she's a PC and Mac person), and raves about it. Uses it on the train to London, and through the car sound system when driving.
She's got some absurd number of CDs stored on it. It's an amazing bit of kit. It's small enough and portable enough that I can't see her wanting a smaller one, especially if battery life is compromised.
I'm tempted myself...