So many answers here already - but simply: 1. Very fast natural light shutter speeds (i.e. beyond 1/8000th second), whereas most leaf shutters might hit 1/500t

So many answers here already - but simply: 1. Very fast natural light shutter speeds (i.e. beyond 1/8000th second), whereas most leaf shutters might hit 1/500th or greater. He talks about some very expensive lenses that can go to 1/1600th, but this is fairly extreme. The downside is a slower (1/200 - 1/250th) flash sync speed.