SDS vs Walker vs Clearaudio

I only have experience with the SDS and the Walker. Sorry I
can't make a comparison for you across all three. Of the
first two, in each of several different VPI turntable with SDS
systems into which I've introduced the Walker Motor Controller
for audition, the system owner and I have concluded that the
Walker made an immediately audible sonic improvement in
comparison to the SDS -- at a higher cost, of course.
.

I can second Rushton's comments with regard to performance with a Well Tempered Classic TT. The Walker outperformed the SDS in pitch stability and spatial relationships within the soundstage. Sorry, no experience with the Clearaudio.

Quick question, I understand that Walker and SDS only works with 110v motor. Since I live in Asia and use 220v motor, for my VPI, I was told that I would need to change 110v motor as well if I want to add SDS. Is there any speed regulator/controller that would work with 220v motor?

I use the Clearaudio. I notice a big improvement in the performance (sound, dynamics) of the Basis turntable (mine is 2001 with Vector 4). Sorry, no experiences with the Walker or something else. It is 220/230V as well.
But a friend of mine has experience with a dc-motor+regulator. According to him this is it!! It costs less than the Basis regulator. He also used the Clearaudio formerly.
batalok

Suteetat, I use my SDS for my VPI flywheel on the Micro SX 8000 II. It is excellent and you can use it with all voltages. It generates the voltage you need on your turntable motor drive. I am living in Germany using 230 V.