I have always found that the more rigid the support, the tighter, more incisive and clearer the sound. Damping of the support by using wood or "absorbers" softens the sound. Marble and glass sounds etched while oak sounds warm etc. I'm old school and have to be convinced otherwise but spikes, cones and inertia allow the table to be as fixed as possible.
This^^^
Which is why I built this.
http://www.theanalogdept.com/images/spp6_pics/C_miller_web/TTstand_1.jpg
Which all I know for sure is it was a big improvement over the floor.