The D700 continues its excellent noise handling at high ISO sensitivity levels, delivering sharp, noise-free photos as high as ISO 6400 and relatively usable ones at ISO 12,800 (Hi 1). You probably don't want to visit ISO 25,600 (Hi 2) too often, though.
As you'd expect, since they use the same sensor and probably very similar processing firmware, the D3's noise for the ISO 25,600 photos (right) looks about the same as that of the D700 (left). The D3 does seem to preserve sharpness a bit better, but the slight differences in exposure that we see between the two will also affect the results.
With a good lens--I used the excellent 24-70mm f2.8 here--the D700 produces very sharp photos. I was a bit less impressed with the sharpness results from the 24-120mm f3.5-5.6 lens which comes as a kit option.
The D700 renders very nice and accurate color, and its outdoor white balance works quite well. Because of overcast weather I had to shoot these at a higher ISO speed than normal--they range from ISO 500 to ISO 800--but a spot check showed that color consistency across the middle range of speeds was very good, and that even at higher ISOs the colors render very well.
Although you wouldn't confuse the D700 with a pro sports shooter, it's fast enough for most other activities, and Nikon's AF-tracking system remains first rate. (ISO 1600, f5.6, 1/250 sec., 24-120mm lens)