I bought one of these today. I normally wear a medium (Scorpion EXO700 and Shoei X-11) but I needed a large in this one. I was actually between sizes and went with the slightly roomier one. It fit comfortably. I will give a review once I can wear it for a few rides. I've never had a DS helmet so we shall see. For $99+tax I figured it was worth a try. More to follow.