Is bigger better?

Ok, it seems that in the country that bigger is better.. Cars, hamburgers, sodas; they all come in larger sizes and it seems that advertising has programmed us to think that more is better.. Maybe that's why we have fallen into the economic mess that our country is presently struggling to dig out of.. This all brings me around to my present dilemma. I had been shooting with the Nikon D2X until the D700 came.. the D700 has essentially replaced my D2X (anyone want to buy a used D2X?).. When the D3 came out, it was a great camera but the pixel size was about the same as my D2X, so why bother.. I decided to wait until the D3X came out.. Hence the D700 in the mean time. Now the D3X is out, I find my self struggling with the cost vs megapixel dilemma.. Talking to friends, the D3 is a great camera and the D3X might not be up to speed in the higher ISO the way the D3 is.. And for a nature shooter, the D3 is faster... Can I justify larger files for more money and slower speed, if the quality of the files falls some at higher ISO.. I'm planning to go to South Africa in December, so the decision needs to be made soon... Or Nikon could just give me one of each to use! Tune in later for more on the megapixel debate..