Not sure why I don't hear more about Knoll's ergonomic chairs: http://www.knoll.com/shop/by-category/ergonomic-desk-chairs http://www.knoll.com/shop/by-category

Not sure why I don't hear more about Knoll's ergonomic chairs: http://www.knoll.com/shop/by-category/ergonomic-desk-chairs http://www.knoll.com/shop/by-category/ergonomic-desk-chairs Please comment if you've used a Knoll chair and can compare it to an Aeron or Leap.