On the other hand I’m sure that beyond a certain point none of us can readily hear speed imperfections, especially not those quoted for the Monaco 2. I mean I know turntable speed matters, it matters a lot, but this is overkill, isn’t it?
No - definitely not overkill.
The gains from stable accuracy are substantial. it’s all about time - the cartridge provides the amplitude of the musical signal but the time element - the frequency - of music comes from the turntable’s rotation, ideally at 33-1/3 rpm.
It’s not a question of what you hear when speed is off, it’s what you hear when speed is both stable and accurate. Wow and flutter are unmeasureable with the Monaco and a few other advanced direct-drive tables (eg NVS). We’re well beyond old standards.
Any aspect of reproduced music related to time - depth, soundstage, transients, dynamics, tonality, etc. - is better or worse thanks to timing in the creation of the original signal. And no amount of downstream electronic wonderfulness can ’fix’ that signal if the turntable rotation is not accurate. These are not just technical considerations, but tangibly audible results.
Perhaps Technics (orig Sony) claim of eliminating direct drive 'cogging' have finally turned the tide for good this time.
Use of spotless motors does this. Equally important is the drive system that controls them.

