depends on the lighting. If the sky is too bright and ur close up subjects are dark, i would prefet whole one stop. if everything is almost evenly lit but requires some minor tweaks in the shadow area....then 1/3 would be more than enuff.
I like the 10FPS of my mk III. I set the bracketing to 1/3, rip 3 shots in less than a second and can do a clean HDR. I love it