what do you think about Zcoil

A friend of mine in healthcare has some awkward looking shoes. They are made by a company called Zcoil. They have a large spring on the heel. The claim is that these shoes are better for your feet and especially for those who work on their feet for extended periods of time because it reduces impact with the spring which acts like a shock absorber. Please let me know your thoughts. Their web site is http://www.zcoil.com