The problem with these is that there is resonance control only in the vertical direction. There is virtually no control horizontally. If you have ever tried to push to opposing magnets together by hand you will notice that they push each other away in a very slippery manner. It is hard to keep them opposed. In order to keep them opposed they have to be firmly captured and held in opposition. Springs have some horizontal resonance control but still not as effective as in the vertical direction.
MinusK platforms have almost identical control in both directions which is their claim to fame.
MinusK platforms have almost identical control in both directions which is their claim to fame.