Thanks for the feedback, y'all... have my main, 2 channel listening system, posted now with relevant pics.
I believe your testimonies answer the question of whether or not the PSU upgrade improves the sound regardless of external DAC input. I, too, love the bluOS as it integrates well with my Roon and has USB output. Also looking forward to the upcoming reviews of the not-yet-released Node Icon.
If I were to upgrade the streamer, I'd prefer one under $2k new but would have to have USB output, Roon ready, and excellent Android(phone) or IOS(iPad pro) app.