I have both, a used Nikon D700 FX and a used D300 DX with 12 MP each. Why? Because FX is just nice to work with, it feels a lot like film. DX on the other hand

I have both, a used Nikon D700 FX and a used D300 DX with 12 MP each. Why? Because FX is just nice to work with, it feels a lot like film. DX on the other hand is the best teleconverter you can think of, turning a 300mm FX lens into a 450mm one.