@atlvalet In full transparency I am an authorized Aurender dealer. That said, I try to be as unbiased as possible in my responses across the forum.
As said above, I used to own the M50.2. It was actually quite a good streamer and server in its day, a huge step above the Bluesound Vault in terms of sonics, and the BluOS platform is quite stable and easy to use. You could easily invest in additional NAD units like the C658 if you want an all-in-one streamer/DAC box that acts as an endpoint for your living room, and perhaps a Bluesound Node for your office. That route is likely the most cost effective and will yield decent, but perhaps not endgame results that you are seeking.
You mention you don’t really want to pursue Roon as you prefer box solutions. There are a few good Roon core & endpoint solutions that are more like a box solution, but I have compared the M50.2 to the Roon Nucleus+ and felt the M50.2 was better sonically. I even preferred the M50.2 to the Innuos Zenith Mk3. There are excellent Roon core solutions like the Pink Faun 2.16 Ultra, but that will net you over $12K for a single unit.
As an Aurender dealer, I absolutely love Aurender’s ability to let its owners step away from computer audio completely and can deliver a significant sonic upgrade compared to the M50.2, but it does come at a slightly higher cost of entry than with where you are with your M50.2. First, Aurender’s streamers get really good starting at the N200 (at $6K) or paired with a great DAC to make it the Aurender A15 (at $8K) - my standards of “very good” are quite high here, meaning it’s worth walking away from analog altogether. The N20 is even much better still sonically at $12k, as is the A20 if you want the DAC built in.
The Aurender Conductor platform, combined with Ravenna network compatibility, allow for you to have multi-zone capabilities. This allows for you to invest in a much better quality streamer/server solution for your main listening room and stream to other Aurender devices in other rooms.
The box solution you seek might also be further fulfilled as Aurender’s large screens and impeccable build with an extra thick aluminum chassis are a joy to look at and handle.
Would you prefer a separate DAC from the server/streamer or one box that combines both? There are pros and cons to both options that I’m happy to talk through on the phone if you’d like.
Feel free to message me direct for more info or keep replying to this thread.