Michael, The D4 offers no MAJOR improvement to my D3S so I am sticking with the D3S. Like Ira, I have spare batteries from my D2H that I can use in the D3S. When I take the D2H to a shoot as a back up, I know I can swap batteries with no problem. I also like the dual CF card slots of the D3S. I dislike the mixed card system of the D4.
I purchased my first Nikon F in 1970, so you have me beat by a few years. Being a native New Yorker, I spent many enjoyable days at the 1964/1965 New York World's Fair. It was only a 10 minute drive from my house. I had to use a Kodak Browine and Instamatic to take my pictures.
The "new" D3S' you mention are all grey market and Nikon USA will not service them. Buy a low mileage Nikon D3S. You won't regret it. You can find them on the Buy/Sell forums of the major photo sites. I would stay away from craigslist and ebay.
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