VPI Speed Controller

Other posts are correct, the SDS is better than the newer ADS.  The ADS is cheaply made and has been the subject of many complaints.

However, you seem to be aiming for high performance.  If you want the very best, SOTA sells a motor-controller-roadrunner combo.for VPI tables.  It has been discussed at length in the VPI forum.

Other ways of improving performance would be the motor-flywheel combo, if they still offer it, and the peripheral weight.

@ joeyfed55-    To be more concise:  Here's something to consider, regarding the VPI Prime's maintenance, if you haven't already:    https://www.youtube.com/watch?reload=9&v=AHmYWT3wKqs    Happy listening! 

@rodman99999

That was a very  funny video.  Putting oil in the top of the pulley to lube the bearing.  Who is that moron?  He certainly doesn't know anything about turntables or motors.
Agree with the other posters.  Keep your SDS.

Oil will migrate, between the pulley and the shaft, down to the top motor bearing.      Letting the motor run overnight warms things up, and facilitates the process.       The option is to remove the pulley, as demonstrated.                    The, "moron" is Mat Weisfield (current President of VPI), who just might know a thing or two, regarding the maintenance and design of his company’s motors and TTs.                      Of course; that’s just my opinion, regarding Mat.     Thus far; I've been very happy, with VPI's designs/equipment.                                            

Had an SDS with my TNT6 for years - loved it!