The shutter on the D3 has twice the design life of the D700. It is also capable of 9 FPS FX and 11 FPS DX compared to the D700's 8 FPS w/MB-D10. With the buffer upgrade it has about double the capacity of the D700. Without the buffer upgrade the D700 has a significantly larger buffer than the D3. Good Luck and Enjoy your Nikons!