Altra has a great advantage with the 0 DROP sole, it takes  a lot of pressure off the body, it makes you stand straighter and makes you're hip alignment improve dramatically.  I have previously used the NEW BALANCE 847, ASICS, KAYANO 19, SAS TIME OUT for which I have changed the inserts to custom insoles, but all of them have a HEEL which makes you're body shift forward in an NON-Natural Alignment. This puts pressure on you're feet and hips and increases pain.  I have flat feet and an injury on my FHL tendon, which left me with issues in the past, 0 drop reduces much of the stress on the foot.<br /><br />The Altra Provision Walker is a similar shoe to the NEW BALANCE 847, a normal leather walker, but it has a great advantage being 0 Drop.  I slipped out the insoles, since the factory insoles are very cheap and put in a Powerstep Pinnacle which does the trick.  The Altras have good cushion and good  sole.<br /><br />The reason I rate it 4 stars is because I feel that the fit is just a half an inch smaller than a size 13 should be, and also since the leather material can be improved upon.  I look forward to the next version of this shoe, definitely worth a try.