Very cool!
I know that people here say remarkably nice things about the quality of the analogue-out of a MacBook, but I found informally that Chromecast's DAC is much better. Of course many people have even better DACs in their amplifier or standalone DACs and just use the Chromecast as a streamer. However, I've got to say that the Chromecast is a wonderful bargain and embarrassingly suitable at the heart of any non-silly HiFi system!