The D700 is a pretty schweet camera, no doubt abut it. It instantly fit into my photography easily replacing the D300 for my EDL camera (I love having full frame). But for many, the D700 has brought up a major question. The D3 or the D700? Since both use the same sensor (as in exactly the same), it is a very good question.
As you can see above, the D700 isn’t really that much smaller than the D3. Attach the MB-D10, it’s the same height. The D3 weighs in at 3.16lbs and the D700 at 2.62lbs (battery included). So just going by size and weight, not a huge difference. The fps of the D3 is 8, the D700 is 5 and goes to 7-8 with the addition of the MB-D10 (depending on battery) so there is a little difference there. Stock D3 & D700 have the same buffer size but now with the buffer upgrade, the D3 doubles that of the D700 (& adding $500 to the cost). So looking at just the specs it’s real easy to see why folks are wondering which was to turn.
That’s until you look at the price. Yeah, the D700 saves you bucks and in this day, that is an important factor. Do you loose something by spending less? You do loose the dual CF slot, you do loose the faster fps going with the D700 but you gain the sensor vibration which so many seem hooked on. You can read the Nikon DSLR comparison brochure or the D700 IB which might help with your decision making.
My answer for most folks is, go with the D700 as dual CF & fps isn’t mission critical for most photographers. Personally, I’ll just be adding the D700 to the D3 fleet because especially now with the buffer upgrade, the D3 solves the problems I run into. Either way though, you’ll have a pretty darn nice machine!