This have become a intersing dicsussion
The choice of a camera is very personal and have to do with the way you are taking photos.
I use my camera only for UW photos.. Landphotos are not my think..
anf therefore features that improve the shooting over water are not intresting for me.
William ask me... you have not been using your D70 for all that long. Are you sure you need to upgrade at all so soon
William you are right. Off cource I dont need to upgrade at all so soon.
but I need a second camera body and I dont like to spend my monay to a new D70s
But i know the limits of my D70s.
The d70s is not for freediving photography the perfect camera.
its the noice and ISOS that i compination with filterphotography and White balance can be a problem.
The D200 have something very intresting for me and my way to take photos.
If you take photos with A priority you can set you camera to increase the Iso automaticly if the shutter is going slower that say 1/125.
In a swedish forum they have dome some test and i just show you the results
Resultat is that the d200 control better the highlights. (I thing it is like the d2X , they just clip the highlights.)
The color is diferent i think that the d200 have they same way to process the colors like the D2X .
3x crop
..undefined
then you have less chromatic abberation, soemthing that i have offen in my photos

and some more photos
D200 + DX 17-55mm
D200 + DX VR2 18-200mm
D2X + DX VR2 18-200mm
D2X + DX 17-55mm
If i would use the camera both on Land and in Water I would not think the same way...
Lambis