Direct drive vs belt vs rim vs idler arm

Belt Drive get a TW Black Night.

Lewm. I am sure that the Monaco's controller is very advanced in the way it responds to the platter speed signal. What the JVC ( Goldmund Studio ) motor demonstrates however, is that its speed sample rate is not unusually high.

Lewm cc Richardkrebs
I dont think the Goldmund numbers quoted are indicative of the sampling rate. I dont think you can count the number of wavy lines on a pcb and equate this to sampling rates. The Goldmund uses a coreless JVC motor. It uses a quartz lock servo. It is more likely that the wavy lines on the circuit board are used to generate a phase signal that is compared to a reference in a feedback circuit. The loop bandwidth of the feedback circuit determines the speed of the feedback loop.
It would be more illuminating if Richardkrebs actually explained what type of motor the Goldmund uses, how its speed correction works and why he chose to abandon the TT self build project with this motor.

the Studio's JVC motor was a good implementation, but the motor was unsophisticated.

"So, Richard, are you inferring that the GP Monaco claims for the speed of their speed correction system are not so earth-shattering or envelope-pushing as one was led to believe, given what Goldmund did two decades earlier?"

Goldmund didn't do it at all! They just sourced the motor and electronics....first from Papst then from JVC when the Papst motor was discontinued. Their claim to fame was the use of methacrylate and in the energy transfer path to drain away vibrations... I do the pink Triangle predated their use of acrylic (and maybe Merrill as well).
IMHO neither Goldmund nor Monaco would have the resources to pull off a dd system in the way one of the Japanese giants would have back in vinyl's heyday.