So far, I'm loving the following features, compared to my old player:
- Sane shuffle mode (the Sansa would randomly select whenever you went forward or back, and you couldn't go back to a song if you accidentally skipped it)
- Much much much faster navigation (though the click wheel is definitely something to get used to)
- Less buggy when it comes to displaying current song information (the Sansa couldn't handle even moderately long artist/album names all that well)
I didn't mention the rechargeable battery and increased storage capacity because, well, those are givens. The only things I might miss about the Sansa, if I used them at all, would be the FM radio and voice recorder.