My 2nd gen Nano just petered out, so I'm currently debating between the 16gb iPod 4th generation Nano or the 16gb Sony Walkman S-series. They are both about the same size and price (~$180). I've heard that the Walkman easily gets 30 or more hours of battery life. How is the battery life on the 4G Nano? My 2G nano got decent battery life (15 hours or so), should I expect the same for the 4G? Does the Genius feature on the Nano work well? I used to own high-end Sony minidisc players and the sound quality was always awesome (I don't think my 2G nano could compare in sound), so I'm seriously thinking of going back to Sony now that they got rid of the stupid Sonic Stage and DRMs. Can anyone attest to the sound quality of the 4G nano?