I do miss What.CD and its catalogue of classical music where it was easy to find the different renditions of any given symphony. It was the best I've seen (not that I've searched very hard since then). Spotify leaves a lot to be desired in that respect.

That being said, Spotify is probably not the best product if you listen to classical. If classical were all I listened to, I would probably still have an offline collection in a Media Monkey library as my main source of listening.