Good shoes whether clarks, ecco, merrills,rockport or many others are important, but more so is to have several pairs to rotate the shoes daily rather than wearing the shoes continously. All shoes have built in elastomer substance of some type and when they get compressed from standing/walking all day, they need time to recover and so the heavier you are, the longer in between wearing of shoes should be allowed. When I was in retail running a 24 hr store (900/day average) I would often rotate a pair of shoes during the day just for comfort .
I think often times we tend to wear a pair much longer than the cushioning life but we don't think about that part since they still look good outside.