Looks: very small and light, lovely to hold in the palm of your hand
Sound: fantastic sound through the in-ear headphones - the best I have ever heard and these buds are wonderfully comfortable. The 4 and 8gb players also come with wireless headphones (very easy to pair with player - the sound quality is very good wireless - probably not as good as in-ear headphones but certainly more than satisfactory) - the only drawback is they're not as comfortable as the in-ear headphones.
Picture: After putting a couple of film trailers on the device (a breeze to do) - see Sony's website for links to free trailers and podcasts specially made for Sony Walkmans (click the walkman sign next to the film trailer and the site recognizes your player attached to the computer and automatically downloads it!) - I was very pleased with quality; such smooth and crystal clear playback. You even get a mini stand so you can watch the screen propped up!
Summary: OK, I've only just started using the player and I guess the real test will come with time, but for now I have put 10 albums on the player, several film trailers and navigated menus with ease. I haven't discovered half the features yet but these tasks took minutes and results are instant and so pleasing. I'm proud to own this player and will look forward to the many hours of use promised for every charge.