These rubbed the back of my heel when I first got them, but they've quickly softened up and molded more to the shape of my feet. They're now blister free and one of my go-to comfort
shoes. I especially like the wider toe box which doesn't pinch my toes. But they are pretty insubstantial, so if you want more support, these aren't for you. As for size, I sometimes wear 8.5 and sometimes 8 in different styles, and the 8 in these is slightly roomy for me, but works.