speaker/stand, couple or isolate?

@gjohns info not valuable without describing the floor your speakers sit on.  

Isolation of speakers eliminates the variable of what kind of floor it is. If thy eye 👁 offend thee pluck it out! It could be a trampoline floor, it could be a cement floor, it could be a suspended floor on the tenth floor. And higher floors are moving side to side 🔛 due to wind and other forces - and in rotational directions 🔄 as well as vertical. People tend to hyper-focus on vibration in the vertical direction 🔝only. There are six (count em!) directions, at least. In the horizontal plane there is an infinite number. 🙀

You want to do two contradictory things:
Minimize the contact area the speaker cabinet has with the floor. This doesn't have to be extreme, but not resting the entire cabinet on the floor is bad.

Minimize the amount the speaker moves in space. The force a woofer has on the cabinet is significant. Sometimes adding weight to monitors can significantly improve clarity and bass.

@avanti1960   Thanks and my apologies.
Currently my speakers are on a ceramic tile floor that's on an underlying concrete basement floor. Cheers.

Now what about open topped stands, the kind of stand that, for instance, Harbeths tend to be put on, where there are only four points of contact to begin with, at the corners?  Those stands are made of either metal or wood, so there's another variable...