Bought a subscription to Quobuz back in February and I have nothing but good things to say about streaming. I don't think I have the critical listening skills that most on this forum has so I wan't speak to the quality of the sound. What I can say is having that kind of a library at your fingertips can significantly change your listening habits. I spend way more time listening now compared to when I was streaming my iTunes library, Pandora or listening to CDs. In fact, I've become a bit of a music whore. I'll literally give anyone a half hour of my time. I find myself listening to genres I never would have considered in the days of physical media.
One of my favorite ways to spend time now is to settle down with an issue of Sterophile or The Absolute Sound and playing every song mentioned in the issue as I'm reading it. I've discovered so many artists doing this. It's made me realize how little I really knew about music before I started streaming.