Manitunc,
One issue I have with very speed-stable decks-- warps and off center pressings are very audible to me as pitch fluctuations. Even with a record clamp, most records are not flat enough or are not hole-punched dead center. As a musician, pitch fluctuations 33.3 times a minute is more than I can stand. My Thorens masks this with a slight motor cogging-- a fault I can live with.
One of my favorite records..."Aaron Rosand plays Sarasate" on Vox-- sounded quite bad on the Oracle. Audible fake reverb, adjacent groove echo, and of course pitch instability. Returned to my Thorens, all was good again.
I think the Rega P25 also masked some vinyl defects.
I believe amps can also hide faults in recordings, thus some prefer noisy carbon comp resistors to quieter, modern ones, and noisy tube amps are sometimes preferred to good chip-based amps. Silence is not a naturally occuring phenomenon, especially in a concert venue.
I suppose if LPs were all recorded and pressed without faults, I can justify an upgrade, but I buy my vinyl for musical merit alone. Interesting thread