The wheel is not the same as the iPod one - it's a clicky one -- although if you hold it down it scrolls through the tracks. Seems a bit slow to me. The thing I do like is it remembers where you left off. So when you switch it on again you are at the right place to continue listening to your audio book.
The picture viewer is pretty good for a small screen. I should think the quality would depend on the original to a certain extent.