The Solomon XA Pro 3D M+ is built with a high arch support and is fairly stiff & should be considered a 'motion-control' shoe (support for pronation). I have a very difficult time finding shoes that fit and support my feet. I have a slim heel, a moerately wide foot, and very high arches. I have also had foot surgery and were custom orthodics. This shoe fits me perfectly and I don't need to were my orthodics! I tried the regular width and it was too tight in the shoe box (Solomon shoes are made to fit faily snug). The only difference I could tell in the extra-wide shoe was more room in the toe-box - exactily what I needed.<br /><br />Disclaimer: I am not a runner and use these shoes for walkng the dog, light trail hiking, etc.<br /><br />This shoe is not for everyone. I don't believe that it would be comfortable it you have flat feet or low arches.  And some people may find that the stiffness and lack  of flexibility a problem. However, for those of us that need good arch support and control will find this shoe a good fit