Toe overlap and bottle cage clearance. The toe overlap is often engineered down in WSD bikes but not always. I ride a 47 cm Cannondale and cannot get toe overlap on it even though it has 700c wheels. The guy who sold it to me was actually shocked at that and has been in cycling for 30+ years. I know the Specialized Ruby and Terry Bikes are designed to reduce/eliminate toe overlap.

The bottle cage clearance is my biggest complaint on my frame. My particular frame (as you can see in the avatar) has a sloping top tube. I can barely fit anything over a 20 oz bottle in the front cage and have to use the smaller bottles in the back cage.