#7. "RE: Is the D700 the optimum upgrade path from D70?" In response to In response to 0
If you like to shoot at 200mm with the 1.4x converter, then you'll probably want a longer lens as well (although the 1.7x converter might suffice). You might want to read the review of the Nikon 70-200 on dpreview. It appears this lens is not a good performer on the FX sized sensor.