>With a D4 you will have a much heavier camera and much >heavier lenses. You may gain in image quality but it depends >greatly on your subjects. With people and sports and dog >photography it is not going to make a visible difference in >any prints you have made. >
I'm puzzled by this response. Make no mistake: I'm not taking snaps. I'm trying for very high-quality dog portraits, candids, and action shots worthy of a coffee table book or the high-end calendars. So far, the superior high-ISO performance, faster focusing in low light, and higher fps has resulted in massively better shots. Plus the lenses aren't "much heavier," as they are the same lenses I was already using. And the camera itself isn't particularly larger or heavier than the D300 with MB D-10 that I was using before. I'm really happy with the D4.