I've been listening to the Evanescence album in mp3 for a while, and wishing I had the CD. I finally broke down and got the CD new (couldn't find it used.) Yep. Sounds *far* better, and my ears are so much happier.
I didn't recognize this track when it started - it had a piano track in it. Where'd that piano come from? Sure wasn't in the mp3 . . .
(Note: I'm serious about audio. Maybe not as serious as some people, but we're still not looking at $5 headphones or stock speakers. YMMV.)