In reply to:
But most of a speakers sound is transmitted through the air.
I call bullshit.
It is my opinion that they did not word the description of how the speaker floats work correctly. You are correct that most of the sound energy is transmitted through the air.
When a boom-car drives by a house, the vibrations that shake the china are definitely not trasmitted through the ground. They come right through the walls.
Reducing unwanted cabinet vibration transference is one of the reasons why speaker cabinets are built so dense and heavy.
For speakers that are not quite as heavy, the theory has some merit. There are still vibrations that are partially transmitted to the floors which
could cause a perceived muddines. Based on typical wood frame construction, particularly of older homes, there can be unwanted vibrations transmitted to the floors. If the floors are built with dense subflooring this is usually not an issue.
For most applications rubber pads are adequate. The Mirage speakers I have came with small rubber pads and that is all that they need for any application. The design of the speaker also helped to reduce cabinet resonances.
