@brunorivademar
All i’m saying is that with regards to that particular measurement idlers seem to have an advantage because of higher revving motors and thus less motor cogging.
I have refurbished a few Garrards. I also have a vintage Exclusive broadcast idler.
My reference TT for the past 30 odd years is a thread drive with 26kg platter and motor that dwarfs most TT's. The large AC motor is driven off of a precision sine and cosine wave generator and separate power amplifier. It is superior to the idlers by some margin.
On the other hand I had a Platine Verdier for a while as a second TT - the idlers easily surpass the Verdier. I swapped my reference TT motor drive over to the Verdier and voila - there's the problem - pee wee motor.
Personally I believe the idler "sound" is not the idler drive itself - in my opinion it is the big AC motor drive that is creating that "drive". The removal of a rubber belt also contributes, but I think the big AC motor is the key.
The weakness in the Thorens 124 is the rubber belt.
The problem with modern TT's is that nobody produces quality AC motors any more. Both my reference TT and the Exclusive idler have AC motors the size of a fist - and they are dead silent - even with my ear right next to the motor spindle.
Finally when AC motors self correct for any lag, they do so in a sinusoidal fashion - DC motors when speed corrected do so in a saw tooth - in other words speed recovery on AC motors is smoother and more benign.