Update on things. Ended up returning the M33, it was a wonderful amplifier, with amazing soundstage width, impressive detail and ease of use. However, it lacked slam, presence, or maybe “meatiness”. Even the best Class D cannot compete with the palpability of Class A/B.
I ended up with a Hegel H390 and holy smokes, locked in what I’m looking for. Sparkly highs, accentuated midrange, bass control, slam and dynamism, air and extension, plus ease of roon integration.
I would still still recommend a trial of the PSB as a speaker without fault. Linear, near full range, detail, mid range and low end without color or a “personality”. Seems true to the source. Not sure I could do any better for the price.