Whether to couple, decouple and dampen, etc., is determined by experiment. Theory does not help because whether any result is positive or negative depends on a wide range of factors. With a suspended wood floor, coupling will mean that the floor will be able to better act as a resonant sounding board itself. That is good, if you want some bass/midbass warmth, and bad if you want to tighten up the bass.
I personally use a Symposium Svelte shelf under my speakers. This thin, multilayer platform is coupled to the whole bottom surface of the speaker enclosure for effective transfer of vibrational energy to the platform. The inner layer then converts that energy to heat. This is an effective way or reducing the shaking of the speaker itself (generally not a good thing for sonics), and dissipates this energy instead of transferring it to the floor. This tightens up the sound noticeably, which is a good thing in my system.
I personally use a Symposium Svelte shelf under my speakers. This thin, multilayer platform is coupled to the whole bottom surface of the speaker enclosure for effective transfer of vibrational energy to the platform. The inner layer then converts that energy to heat. This is an effective way or reducing the shaking of the speaker itself (generally not a good thing for sonics), and dissipates this energy instead of transferring it to the floor. This tightens up the sound noticeably, which is a good thing in my system.