>When the D300 was introduced, I decided its specs did not >warrant an upgrade from the D200. I upgraded instead to a D700 >when it became available, since this camera represents a very >significant improvement versus the D200/D300. Similarly, I >also will not upgrade to a D600/D800, since they don't meet my >criteria for a worthwhile upgrade from the D700. My advice to >you is to get a good used D700 and apply the money you save to >an FX zoom or prime lens. The bodies of the D200 and D700 are >quite similar.
A few of us indeed didn't like the D300 because it didn't drastically improve image quality...the D100 to D200 was a much bigger leap than D200 to D300, imho. But for others, the D300 was a huge upgrade from D200, D2-series, or other bodies.