I can't advise between your options but can comment on the Aurenders. I went from a home-built server with a lot of top-end components to an N10 and the N10 blew the server away.
But the app. It's terrible (others will argue). Aurender is not responsive to improvement requests, from me and many others, including on forums where their US tech maintains a presence- yeah, we'll look into it. But nothing. My comparison is to JRiver. I'm not looking for a JRiver experience from their app, but there are certainly many areas where they could make improvements. Bottom line, however, the app works.