I have a number of pairs of Chaco sandals, clogs, and boots; all are incredibly comfortable for longer period-wear. I will be returning these, unfortunately, as they are much larger trail shoes than I anticipated, based on the images on Amazon. Nothing wrong with that, although at glimpse on the site they looked more like trail runners. The Graysons remind me, look- and feel-wise, of Merrell's Moabs. The Graysons felt as if they'd breathe fairly well, and in the time I woore them around the house, this seemed to be the case. Size-wise, they felt large: I wear a 10.5 for the other Chacos I have, and these felt 1/4-1/2 size too long; width-wise, they felt good.