I believe a cheap experiment would be to put some sort of inner tube, perhaps from a motorcycle tire, under the table and inflate it till it "floats". That should let you know more for little $. I have a VPI Classic that sits on a very old VPI isolation base. It has a sandwich platform, metal outsides over wood, and four foam wrapped springs in the corner. That sits on a wood rack I made, and on a hardwood floor. I can make the arm skip if I step near too heavily, but there is no acoustic feedback.
