I have Aurender and am trying out Roon right now on an old Mac with Qobuz and some of my own CD rips. I love the interface of Roon and it has helped me discover new music easily. The SQ of Aurender as slightly better in my system—better clarity.
Until Spotify has an HD tier, I may run both Aurender and Roon. I could imagine in the future selling my Aurender, buying a dedicated Roon server, and canceling my Spotify. We will see.