So very true. Rdio has totally won me over due to the mere fact that I can much better discover music within their applications. Spotify has been sleeping on the job with regard to app design and implementation. Rdio's apps embarrass Spotify's.
Signed up for the premium plan last night and am already hooked on browsing their huge collection of albums, songs and playlists on the website with one-click syncing to my iphone. Does a great job of helping you listen to music offline easily.
Can synchronize your online library with your iTunes one at home too.