Here’s an unsolicited opinion piece I’m going to sling your way. So far, three things have stuck out to me after a day of using Spotify (and about 10 years of iTunes).
Any Song? Really?
Magically, Spotify does seem to conjure up entire albums, tracks, artist info, and you can instantly listen to them in their entirety. iTunes has a store, that’s fairly confusing to get around inside of, and gives you samples taken from arbitrary points in any given song. A great feature of Spotify is the ability to share tracks via URIs. If you want to recommend a track to a friend, for instance, you can right-click, copy the Spotify URI, and when they click it, it’ll fire up that track in their Spotify. No more zipping, posting, Dropboxing, FileShuttling, or whatever means of sharing local files did the trick.
Context
iTunes seems to maintain a clearer ‘current state.’ A user can hit command+L and will be shown the last-arranged or chosen tracklist (the player context) and the currently playing track within that context.
Spotify has search results, which don’t play sequentially. It also has a dynamic ‘play queue’, which functions more or less like the iTunes DJ list. Probably just something to get used to. However, my current queue has a list of tracks filling the screen, with a status message at the top indicating ‘0 tracks queued’. Hmmm.
AirTunes
At home I quite often stream music from iTunes to my stereo system. Spotify can’t do that by itself.
Equalizer
Switching between laptop, two monitors at home and work with different speaker setups, and using AirTunes at home, I keep a few EQ settings in iTunes for bass and treble control, mostly. Command-Option-2 brings up the window in a jiffy. Spotify doesn’t seem to have any EQing at all, so my spoiled fine tunings are simply not there.
Conclusion
Off the bat I feel like I’ll still keep a library of local music files and access it via iTunes. iTunes still holds the cards with the iPhone: syncing, backups and apps. Spotify will see heavy rotation when I want to find new music or socialize playlists. It just has a seemingly infinite amount of music, and after paying the premium fee, the quality is plenty high enough for me. It’s also kind of nerdily rewarding to mess around with new software, so at the very least it’ll definitely function as that ‘new toy’ for a while.
Edit
I added some extra thoughts shortly after posting this one. Check them out here.