I have both, they are 2 different beasts. Personally, I like the S5 for Landscapes and Portraits and really anything that doesn't move. The D200 is more of a General Purpose camera.
What are you wanting to use the camera for?
welcome to TPI think this is where the S5 really excells. The straight out of camera images are just fantastic in comparison to, well, any other camera I have used.The colours that come out of them are just about spot on whereas I found I always have to do more editing with a D200.