Anyone try decoupling speakers from the room?

"My main purpose is to keep the floor from resonating, IMHO it works well."
http://forums.avguide.com/viewtopic.php?t=3588
Please see the link above for an explanation of Sound Transmission.
Suspending your speakers will do nothing to diminish the transference of Air-Borne Sound.
Air-Borne Sound needs to be of a high decibel value, and the correct frequencies to make your floors 'resonate'.
The Air-Borne Sound however will quite easily 'pass-through' the floor structure depending on its insulating and transference properties.

Structure-Borne Sound will be induced into the floor by both Air-Borne Sound and physical impact or vibration.
If your speaker cabinets DO vibrate sufficiently (most don't) and are directly coupled to the floor structure, they may induce Structure-Borne Sound Transmission.
If your speakers are DE-COUPLED from the floor (and this can be done via spikes OR insulating material, there will be no significant transference of the cabinet resonance into the floor structure.
If you do not in some manner prevent the speakers form moving (ie bouncing), you will be degrading the sound.
It is also important mostly, as others have written, to align the Mid-range and Tweeters with the ears in the listening position.

If the speaker cabinets waffle (light weight and not heavily braced speakers) then suspension will make a difference to the sound for sure...sound reinforcement speakers like JBL's fit this category as do thin wall cabinets such as Harbeth's.

Is it better...the eye of the beholder is what counts...

well, yea, my ex got the house and I got the speakers.
worked out great!!!
jb