Vibration damping or isolation products make a very significant difference in the sound. The thing is, so many believe "more" is necessarily better; I have not found that to be the case. There can be too much, which results in a dry, lifeless and analytically clean and non-musical sound. So, it is like so much else in audio, a matter of taste and tuning and experimentation. I don't know of any magic formula.
Isolation stands: snakeoil?
I understand that turntables are uniquely effected by vibrations due thier sensitivity to that kind of energy. But here’s the thing: most turntables, especially decent ones, have vibration control measures built into them via footers and various construction techniques. So, the question is: are turntable stands / shelves with isolation features actually beneficial or are they just horrendously overpriced accessories for audiophiles?