whats the real difference between the sensors in the D60, D90, D300... i know none of these are full-frame, but I currently have a D60 and really want/need to upgrade. Since I live in Brazil, I was going to purchase a better camera body and have my parents bring it in July. the D700 is a possibility since its full frame, but I don't earn money in dollars, I earn money in Brazilian Reals. the photographer I worked with told me that there is little actual difference in the sensors from D60 to D300. for a better sensor, he told me to go for the D700. he emphasized improving the lenses. but i wanted a second opinion.