It's been a while since I'm a Premium user in Spotify, so I didn't notice any changes made for Free users.
Today I had a problem with my credit card and my account reversed to Free. Suddenly, my app got a better interface! What I liked the most was a "Recommended for you" section in my home page, recommending playlists based on musics I had listened to recently.
Yes, I know Spotify always had features like this, but this one was really on the spot, there's no comparison between this and what I have now with "Discover". Music recommendation, for me, always was Spotify weak point (it pales in comparison with Pandora, in my experience), but this looked like a big improvement in this area.
Then I updated my payment info and returned to Premium. The interface changed to the old (worse) one, and the "Recommended for you" section disappeared.
I'd like to know if Premium accounts will get these improvements also.
I immediately went to my playstore to see if there was an update and I didn't not see Spotify. So I paid for the premium and it went back to the ugly looking interface. As paid customers, we also deserve a nice interface as well