10-28-2011, 08:58 PM
I have a D700 and have had a D300s and frankly will be buying another D300s if Nikon does not soon produce a successor. I have never had an AF problem with either and frankly would consider having both bodies if i were doing the kind of work you do. They use the same battery grip and it is easy to interchange the lenses. In terms of IQ, they are very similar, but the FF gives a better colour rendering IMO. The menu systems are identical and the ergonomics as well. I would use the D300s for animal pictures and sports, if you do that and the D700 for portraits and low ISO shooting. I probably don't help you much, but having both bodies is cheap life insurance and the D300s use 2 cards, one CF and one SD and it works superbly.