>2. IQ If not THE best, the D3 has one of the best DSLR sensors >and supporting chipset units made to date by any camera >company. There are individuals who have written about going >from D3 to D300 and back to D3. Why? Because the D300 while >a superbly built and lighter camera, plus a fantastic bargain >for the price, just doesn't match the D3 image quality. It >gives the D3 a good run for the money and is much lighter and >easier to tote, but it isn't a D3. The D700 has the same >image sensor as the industry leading D3.
You said it. I have both, and switch back and forth between the two in order to avoid changing lenses. When processing a wedding, I notice a significant difference between the files. While the D300 has an excellent sensor, a huge improvement over the D200 for sure, they just don't compare to what comes out of the D3.
This is really the only reason to get the D700. The sensor of a D3 for $2000 less.