Made up my mind. I am sticking with my D7000. Why? Surprisingly my main reason isn't cost. It has to do with my skill and knowledge level.
Being honest with myself, I know I have been lazy with this camera. I barely know how to use it. So many features I have not learned how to use. So, I ask myself. How do you know you need a D700, or a D600 when you don't even use this D7000 anywhere close to its full potential?
Whoa, talk about hitting yourself right between the eyes with the truth! Sometimes I have to do that to break out of the cycle of thinking I find myself in. I'm such a blockhead sometimes!
So I am taking myself back to school. I have some good books to read and I am going back to square one with my D7000 and give it a chance. Maybe this is all the camera I really need. After that, say maybe in 6 months or even a year, then take stock. By then there may be some good deals in an FX if that's where I decide I need to go.