Many people who would like to stay with Nikon and buy into FX for the true 35mm film based FOV, are trying to decide on the D700 now or wait for its replacement. FX can be more of a want then a need for a lot of us. I personally hoped that the next model would be the perfect one camera solution with a combination of lower noise, higher ISO’s, 16-18 MP’s. It would do low light, portraits, sports, candid’s all in one body.
The decision to buy a D700 now should in part be based on what do you currently have, and do you want a one or two camera solution for your photography. Most serious photographers would want two bodies as part of their system regardless. So if you’re working with two bodies, it would sure be nice if those two were similar, maybe share a grip and batteries. I know that I would want to feel comfortable going between both, and be able to set them up in a similar fashion, so that either could be used without thinking.
The cost of moving into any new model will be a lot more, and plays into the decision as well. The D800 will most likely not share grips, batteries and memory cards with the D300, but possibly the D7000 (which does have a different battery, grip and memory card). Buying two new cameras, say D7000 (DX) and D800 (FX) would not be an option for many people. Should you hold onto something like a D200, sell it now at a loss, or sell it for a bigger loss in six months. If it is your only DX camera my suggestion would be to keep it for those candid’s and family shots.
In reviewing the D700 my first impression is that almost everything is good. The only thing that I am not crazy about is how the memory card door opens, I would rather have the D300 card lever on the back rather than the sliding door. I like the fact that you can force a FX lens into DX mode and get the crop factor, but you only have the one 1.5x crop option. I am not sure forcing DX is a good choice, a typical jpeg will be about 2,500 KB, so you would be better off cropping in post processing. The D700 is a very nice FX camera with less noise at higher ISO settings.
If the D800 is a 16 MP camera, the file size in DX would go up to about 3,400 KB. Not a huge difference but a bigger file. If it is an 18 MP camera then you’re looking at some very useable DX crops over 4,000 KB. The high ISO performance of the D800 will likely be very close to the D700, given that the MP’s are increasing. So the D800 would gain more MP’s, a 100% view finder, more crop factors, video and an extra card slot. Certainly items that would be nice to have in a FX or any camera, but not a deal breaker over someone looking to buy a D700 for the holiday.