I am very lucky to have got my 200 already. I've sold almost everything I own except my FM2 and my 17-80. The things I have noticed so far (in no particular order) are... it focuses much, much faster than my D70 with the 18-70 and much more quietly. Having the most used controls on buttons and knobs is going to be a huge plus. The battery does seem to run down more quickly (whether this is because it is a new battery that needs some warming up, which I have read on this forum is relevant/irrelvant.) Or whether it is because I have spent so much time examining my images on the lcd, or whether it actually uses more power I don't know. It is going to eat your CF cards. I only have 512Mb cards, I was used to shooting raw with my 70/50. I am now shooting jpeg norm. An empty 512 Mb card will hold 30 Raw compressed images. High iso images do seem noisy but, the temptation is to zoom in a very,very long way and so this may well not be fair. You are going to notice a huge difference in resolution. I know much has been written telling you why you won't but I think you will. For me it has been like comparing my 35mm chromes to my 645 chromes. A big leap forward. Even at 7 by 5 inches you feel you can swim in the images. If you thought that the 70 was complex and hard to master then this is much more complex. That said you will be on familar ground and the curve won't be as steep this time round. It feels beautifully built. I am always careful with my cameras. I suspect that the build quality is of more importance to people who have more than one camera hanging round their necks clanking into each other.
Good luck. Money very well spent. Thank God for ebay!