The only issue with shooting at 1/250 sync speed is that as said already, you need to stop down until you get the exposure right, with the downside then being large DOF. To get shallow DOF in such bright conditions when using flash for fill, you either need the Hi-speed sync, or some ND filter to cut the light entering the lens to a level where your meter shows 1/250 or slower shutter speed is required for a correct exposure.