I added an SRM Silent Base a few months back and from getting the motor detached from the plinth and using the stainless 'cones' there was a nice drop in noise.
I`d guess about 30% of what the Groovetracer subplatter did in that regard.
Up until till now, the Groovetracer Reference subplatter was the single most noticeable improvement made (besides cartridge) it really is amazing what it did to lower the noise.
Well, I pulled the Rega RB700 tonearm with its Groovetracer counter weight off and put on a new Origin Live Silver.
The Rega arm is nice but the Origin Live is amazing....
Right away it sounds really good and should improve once the wires season/settle in.....Very happy that I made the change !