I received the ultra boost in ash pearl size 8. I am a 8.5 in Nike sneakers. Based on the reviews I ordered a half size down. They fit perfectly. The reason why I purchased this shoe is because I needed something breathable for power walking around my neighborhood. There is absolutely no heel rubbing in this shoe and they provide a fantastic fit. These fit me way better than any of my nikes. They provide a lot of support and I have a back injury. I walk in them for 1.5-2 hours every day and my feet don't hurt. I would recommend these for running, walking, casual wear and other athletics.