We're using Wellfloat Delta's in between the stands and the (concrete) floor replacing the typical and relatively simple spikes.
These add a sense of relaxation, calm and harmony to the overall presentation. Less resonance and distorsion basically. It's as simple as that.
The TAD stands do provide a very solid and stable foundation to the speakers but do not really add any "intelligence" in terms of resonance control.
We have not tried the Delta Extreme's. These could be reasonable for the CE1TX though despite the high cost.
/ Marcus