Agreed. With modern emulsions, 6cm X 4.5cm is very adequate. You can always increase resolution by going larger, but then for the same framing, focal length increases, and for the same aperture and shutter speed, DOF suffers. Sometimes, that's fine, sometimes you can just tighten up and lengthen exposure. But 645 is still a great format for 90 percent of shots. I've seen landscapes from 645 cameras that I could not tell weren't shot on 4x5.