I ask this because if you feel the speed hunting servos of DDs like the GP Monaco, Rockport Sirius, Brinkmann Bardo, Technics SP10 etc are a limiting factor, this wouldn't apply to idlers and rim drives like my Salvation, Saskia, Lencos, Garrard 301/401, where the speed is "set and forget".
In my tt, the torque is high, the platter weight is high, the speed is set and chequed w/a strobe, and there is no feedback mechanism to alter drive based on what the platter is doing. The designer could never get a feedback servo to work w/out squeezing the life out of the sound presentation. Only when he perfected a 100% analog/non servo feedback system, matching exteremely high torque to high platter mass, did he manage to get secure speed stability w/full analog bloom of sound. And I do believe he has suceeded because the sound is in equal measure: detailed, neutral, transparent, propulsive, nuanced, tonal and textured.
Do you have time for this kind of approach?
As a result, I do believe tt's should not just be categorised as: belt OR servo-controlled dd, but belt OR servo-controlled dd OR non servo-controlled idler/rim.