Fits fine on the shoulder but not alot of room under there. The flap is really nothing and inconsequential. It's just small and hides the pocket and zipper. Flaps over very easily. As far as comparing it to the Sienna. This is so different. The weight is miles apart and the amount it holds??? Maybe the same or the Katy holding more since it's kinda boxy and Satchel shaped.
The color and leather are it's high points and the style grows on you the more you look at it.