Based on what I've been able to prove to my own satisfaction by tweaking a VPI belt-drive TT, I'm in agreement with Halcro regarding the merit of a non-suspended TT, but sited on a platform that provides a decoupling suspension.
An unsuspended TT with a standalone motor, combined with a belt made of non-compliant material such as thread or tape, should in most cases have superior speed stability relative to a suspended table with a soft rubber belt. The unsuspended design fixes the geometry between motor & platter. With a suspended TT, geometry & belt tension change constantly with variations in torque on the belt caused by modulation in stylus drag and plinth movement in the lateral plane-- resulting in variations in pitch.
Nonetheless, decoupling the TT from earth is still beneficial. If you can rap the rack with your knuckles and hear the sound through the speakers while the stylus rests in the record groove, then it's likely that the rack is acting as an antennae for LF vibration from earth or from AC transformers on the lower shelves or from acoustic waves from the speakers. Most of this energy can be absorbed in very low-frequency vibration by placing the entire suspensionless TT & motor assy on a decoupling platform of air springs or mechanical springs.
As an ancillary benefit it's easy to level up the TT by shifting the springs around.
