My main source of music is streaming. I started with free version of Spotify initially. I play using Spotify Connect in my Denon x4500H. I upgraded to Spotify premium a couple of months ago in a hope that I will get a huge quality improvement. But to my disappointment its not the case. I have a more than 40Mbps internet connection quite stable and good and the settings in Spotify is "Very High" for streaming.
Even some tracks on you tube, play much richer and dynamic than Spotify. Last week I opted for Gaana+ subscription as well. Again not much different from the free version of Gaana.
Just before writing this post, I played song on my laptop connected to AVR via hdmi, I played following version. MP3 , Ganna+ and Spotify. I couldn't make any difference between mp3 and Gaana/Spotify. Its very unlikely that my mp3 file is of superb quality.
Another test I did is with flac file whihc scores over anything.
My conclusion is not all the paid content is of high quality. May be only 20-30% content is HD or higher rest everything is compressed or as good as mp3 only.
Lets see who agrees with me.