>In my experience, it was definitely worth it. However, my >upgrade was more drastic--D90 to D600. The IQ and low light >performance cannot be compared. I was at a wedding last week >sitting about 30' from the front, shooting with a 85mm 1.8g >and the cropped images were outstanding. The resolution was >more than I could have hoped for.
The 85 1.8 was one of the lenses I bought for my camera upgrade and am also impressed. I used it during a cross country meet and was surprised at how often it grabbed correct focus with moving subjects. It was amazing over 2.2 but it was a little off at 1.8. Not surprising. This is a portrait lens and can focus fast enough with the D600 to be used for sports. BTW I bought the old AF 1.8 D the new lens may even be better. All the runners seemed to be jumping off the image with nice background bokeh it produced. I also played with my lanscape lens and was again impressed. The focus grab just seems to be dead on and quick.
"Cameras and lenses are simply tools to place our unique vision on film. Concentrate on equipment and you'll take technically good photographs. Concentrate on seeing the light's magic colors and your images will stir the soul." Jack Dykinga