Lewm - same experience, but from the motor & power supply mods we did, the cogging in the early motors on the SOTA was significant. According to our tech the "cogging" was induced by shortcomings with the power supply regulation on the papst motor board, not the traditional cogging as in poles/slot rotation of the motor itself. That being said, the motor/platter should be rigidly coupled for stability, and obviously SOTA addressed this issue later by mounting the motor on the same chassis as the platter & arm.
After the SOTA I temporarily used a Townsend Rock with the ET2 and the stability of the fixed plinth design was apparent, despite the sloppy build quality of the early Townsend.
After the SOTA I temporarily used a Townsend Rock with the ET2 and the stability of the fixed plinth design was apparent, despite the sloppy build quality of the early Townsend.