Great camera,I also picked up one up at a very reasonable price.It has a proven track record.I have tried the D600 and it just did not cut it for me. There are now many choices ,it does not always have to be a current model.
I too have a D300s and D700. Use the 700 for low light and wide angle work. The 300s is the everyday camera and can't be beat when I use my Sigma 150-500 for the extra reach. I also like sharing batteries, CF cards and the grip.