I've tried both sprung and unsprung suspensions on the same TT (VPI TNT III.) The best result was achieved after converting the TT to a hard-mount suspension & coupling the plinth to a large dump for internally generated vibration(sandbox). The vibration dump was then decoupled from earth vibrations using heavy springs. This combination of coupling & decoupling made a larger difference than any other upgrade I've thrown into my analog front end. This includes comparing SME to Graham, Oracle to VPI, and BAT to Atma-Sphere.
Doubtless the sprung vs. unsprung debate will continue. A sprung TT is probably a manufacturer's best bet to accommodate the widest range of rack & room variables. An unsprung TT that is freed from rack & room variables is probably more difficult to design and more expensive to manufacture due to exotic laminate construction & massive structure. Fully integrated rack/TT system like Rockport are very expensive.
But in the end any TT is probably only as good as its platform.
Doubtless the sprung vs. unsprung debate will continue. A sprung TT is probably a manufacturer's best bet to accommodate the widest range of rack & room variables. An unsprung TT that is freed from rack & room variables is probably more difficult to design and more expensive to manufacture due to exotic laminate construction & massive structure. Fully integrated rack/TT system like Rockport are very expensive.
But in the end any TT is probably only as good as its platform.