This is a pretty sticky topic. One likes to decouple, the other to ground the speaker.
In my case, I use Vandersteen's. Mr. V. believes that grounding the speaker to the floor is the best method.-See his newest speakers- they have a 3 inch granite base that keeps them from moving so that the speaker output is maximized (okay, I can't say exactly what he did, but that is the gist).
I also live in wood frame house, and adding the granite plinths made a significant difference for the better.
Bob