Suspensions on turntable...really effective?

With all due respect to the OP, the question posed is a bad one from a scientific point of view; it cannot be answered simply or with a simple experiment.  The responses that go in all possible directions so far are consistent with that fact.  The huge variety of turntable suspensions (also counting no-suspension as a form of suspension) offered in the marketplace is further evidence that there is no "correct" answer to the question.  In my opinion, those who try to develop suspensions for turntables must be very brave; it's a pit of snakes.  No matter what one does, there is a new problem that comes with it.  Personally, because of this, I favor unsuspended turntables, massive plinths, heavy duty shelving, concrete floors, etc.  If you can afford a Vibraplane or Minus K, they're probably superior to most built-in suspensions but not perfect.  For one "concrete" example, I've set up a second system in my basement, on the poured concrete flooring.  This did great things for image solidity and reducing spurious noises that can be produced when the needle is disturbed in the groove, with a Lenco that I had earlier auditioned in my "upstairs" system.

A few guys mentioned great bass from a Linn. While I can like the sound from a well set-up Linn, I always find the bass to sound "light", not to say lacking.  I've owned a SOTA Star Sapphire Series III; the bass was downright muddy, could as well have been due to belt stretching as to suspension flexing.  However, I do agree that later generation Sota's are better in this respect.

Dear Ct, What GK was referring to regarding the tendency of magnets oriented such that like poles are facing each other to want to slide sideways, around rather than toward each other, is indeed happening in your Verdier turntable.  Only the mating of the male and female elements of the bearing holds the platter in proper position over the base; otherwise the platter would slide off onto the floor or shelf.  This means that for better or worse there is always some additional friction generated, in the horizontal plane within the bearing assembly.  No criticism is intended; it's a fine turntable for sure. No design is perfect.

Likewise, every magnetically levitated shelf I've seen has some "stops" built in to it to prevent side to side motion of the levitated element of the shelf.

GK, Gases are compressible too.  Air is a mixture of gases; would it be so wrong to think of air as a gas?  If so, are the physics of compressing a gas the same as compressing a liquid?  Which is to say, do liquids obey Charles' and Boyle's Laws?  I cannot recall what I undoubtedly learned in college.

Dear Ct0517, To answer your question, I have two systems.  In both cases, the drivers are based on electro-static principle.  In one case, yes, the ESLs are driven by OTL amplifiers that do generate a lot of heat, but never enough to raise the room temperature by 10 degrees Fahrenheit (about 5.5 degrees C).  And no, I have never perceived that the heating of the room, such as does occur, has any effect whatever on the sound. (The other system is based on Beveridge speakers which are driven by Beveridge direct-drive amplifiers built into the base of each speaker.  Thus no audio step-up transformer in the signal path. Those amps use a solid-state input stage and tube outputs [4 per chassis] that have no measurable or perceptible effect on room temp at all.)