I recently purchased a Zesto SUT for an EAT eglo petite tube hybrid MM/MC phono stage. The overall sound from the Rega Aphelion2 cart is fuller with the SUT with MM gain settings compared to without SUT and higher gain on PS. The SUT adds a bit of transformer hum, but cuts the tube hiss. This is not noticeable at normal listening levels, only when I put my ear right next to speakers with nothing playing.
I am also thinking about upgrading my PS, and given the various flavors of noise, I may tend towards a SS PS. No idea what kind yet.