I feel there is room for improvement over the soulseek network, though that's about the best there is right now. It doesn't take advantage of downloading from multiple peers (like torrents), quality is good in practice but hard to be sure until you listen, and is missing rare / non-western music.
While streaming apps offer a decent value, I don't like the level of lock in. I have music from CDs and other sources that are a first class part of my library, and using only a streaming app would make them harder to access.