>As an owner of D300and D700, I don't see the "magic ingredient" that >some assign to the D700.
I'm not being rude I promise, but if there's no special ingredient in your d700, you may want to have it serviced or sell it The price difference between the two is quite significant. That, and there is a HUGE reason why professionals industry wide use the FX sensor, for that "special" ingredient.
I'm in no way saying crop frames take bad pictures, in fact they take breathtaking pictures. But under the majority of circumstances the ff sensors will outperform the smaller crop sensors across the board. The magic ingredient is probably the dof, dynamic range, noise performance