We have used a Minus-K negative-stiffness vibration isolation platform with our in-house scanning tunneling microscope but others have used different techniques. We have also used a two-stage pair of plates with bungee cords and find that when the cords in the two sections and the masses of the two plates are optimized this gives better results with the STM. However, it is inconvenient to use because it is much larger. I have seen that others have placed the STM on a granite slab. However, I would think that this technique would only be effective at higher frequencies because the block would move in response to the stimulus at relatively low frequencies. However, I do not know the sensitivity of the STM to vibration at different frequencies. Please give me your advice about how these two systems would compare with a typical low-mass in-house STM.