When Kim refers to small DOF, I assume we're talking about a situation when you are using fill flash on a bright, sunnny day. In such a situation, a slower shutter speed (eg 1/200) would necessitate a smaller aperture. With a faster shutter speed, you might be able to use a wider aperture, with corresponding shallower DOF. You would also be able to have more control of the light balance between the flash and the ambient light.
But I agree with the other comments. Everything comes with compromises. Leaf shutters generally have a slower maximum speed. I've got a few (Yashica Elctro 35, Mamiya RB67 and Mamiya 6) and they all max out at about 1/500. Most modern DSLRs can flash synch almost as fast as this (plus go much faster with FP synch), so there's no real advantage with the leaf shutter. Its not like we're still stuck in the 70's with 1/60 flash synch speeds. Admittedly, there are faster leaf shuttered lenses, but they tend to be costly. I think that the days of mass produced leaf shutter SLR systems have come to an end.
Kim, if you're keen to have a play with a leaf shutter lens, the prices for quality, second hand medium format film cameras are at rock bottom. Some, like the Mamiya RZ67 will allow you to add a digitial back if finances (or second hand prices) make that viable in the future. (Hasselblad have similar options, but their second hand values are still quite strong).