I'm a big fan of "floating" the speakers. I had Eden Sound make me two Terrastone plinths for my B&Ws. The sound is far superior to coupling with spikes.
A recent thread about speaker/floor isolation
OMG!! I recently read a forum thread here dealing with speaker isolation from the floor. I had a pair of 1-3/4" maple blocks laying around unused so I thought I would place them under my Legacy Audio Focus 20/20's on carpet. I can not believe the difference. I am in awe! The sound stage is improved, the bass articulation is unbelievable the speakers are now showing me what they can really do. Everything from low end to treble is greatly improved. Whoever started that thread, thank you. I am now enjoying my system so much more.