As my Wendy says, it's a matter of age!
We currently have a Zebra mat with a foam underlayment on concrete and we're feeling the impact.
Since we're moving to another building, we were going to build a floating floor, ala http://www.judoinfo.com/tatami.htm
but there is already a padded wall to wall carpet on the floor. So we're wondering if the floating floor will make enough of a difference in impact absorption on older bones to warrent the cost.
We have the money, half of the mats and a large carpeted space. What would your dream mat be?