VPI Avenger Reference + Stillpoint Ultra V's

In my experience it's a bad idea. I tried it with an Aries 1 TT and ultra Vs. had bad distortion on any dynamic peaks. The trouble is that you're essentially decoupling the TT from the base, but not the motor. That means that the lateral force from the motor is met by looseness from the stillpoints, interfering with the ability of the stylus to track the groove.  I discussed this with a director at stillpoints (sorry forgot the name) and he concurred with my diagnosis. In the end I went with brass footers directly coupled to turntable plinth and to base. Hope that helps. 

In my experience, there is nothing worse for my VPI than the Gingko platform.  It really muddied up the sonic picture.  I did have great success with something called Bearpaws.  These are very large/heavy cones - solid brass (I think brass).  These were extremely effective.....a big upgrade for my turntable....much better than with the standard feet.   I have a VPI Superscoutmaster/rim drive/Classic platter/VPI 3D arm.  The people at Bearpaws are very nice...if they don't work on your table he gives a refund.

I think Stillpoints under a VPI table could be beneficial, if the entire rig is set on a solid platform/shelf first.  Stillpoints would then be placed under the solid shelf, so that they would serve the same function as the rollerballs in a Gingko platform. This is a more expensive way to do what Gingko is aiming to do with reductions in acoustical feedback to the turntable.  Gingko uses squash balls; Stillpoints use expensive bearings.  Most Gingko platforms require that the entire turntable rig, including motor, be set on the upper platform, so the whole thing can be suspended.

I agree about setting the whole thing on the same shelf, @goheelz .
However I think Stillpoints claims that the effect is greater when you place their footers closer to the component, so they discourage using them under shelves. My own solution to this problem was to buy a used Vibraplane on eBay. It cost less than the price of one Ultra 5, and made a significant and important improvement. Of course you have to make sure you get one in good shape, close enough to transport it yourself (they're delicate). I also found that the brass footers sounded better if they're not sitting directly on the Vibraplane's surface (I use those Weishi graphite blocks).