After unpacking, I experienced the same disappointment, like many other reviewers. The adhesive layer was dried and unusable almost all pad. I resorted to using the double-sided adhesive strips of TESA.
The spikes are extremely sharp and scratch easily massive (!), The laminate / package. The supplied stainless steel washers are a joke! After half a nervous breakdown (because the subwoofer repeatedly slid off the discs) I simply "glued" the felt pads supplied with a round cut TESA Power Strip under the spikes.
The attachment to existing subwoofer feet is most often be a problem. I stuck the spikes just beside the normal feet. The subwoofer will depend then about 1 cm higher in the air.
The sound is in my opinion unchanged after. However, I hope that the next blockbuster drop the glasses of neighbors not back out of the cupboards. ;-)
In summary, I think, however, that the natural resonance of the subwoofer is considerably reduced by the spikes, in combination with the Flizgleitern.
Compared to other bumpers made of hard rubber, I think that the DynaVox boxes spikes despite the aforementioned shortcomings are a better choice, since the contact area with the ground is only needle tip.
