I'm sure you will do well. (I had thought you might be shooting in "auto" white balance--which washes out in some shooting conditions, especially sunsets, etc.). I assume you traded in your gear when you got your Canon stuff. If not, I might be interested in the D700 body. I have a friend who is a much better photographer than I am, and shoots Nikon. So when I have problems, I can always call him to find out what I am doing wrong. Another thing I have learned to "sharpen" my focus is to shoot with a higher f-stop. I was shooting wide open. I found it was better to up my ISO. And my camera does not seem to have any issues as long as I stay below 6400.
Most of my shooting is in Aperture priority. So I just decide what depth of field I need, and then crank my ISO to get the shutter speed I need. Good luck!

Hi Cheryl, I have had some of the same feelings. I am shooting with the same camera and most of your same lenses. However, I have felt the D700 exposure was a little more accurate and could handle noise much better than my Canon friends. Part of it for me was to learn my camera more. And gradually I have been able to get better shots. I am shooting nature, primarily birds. Perhaps you could find a fellow Nikon shooter that is more advanced that would be willing to share tips. I download my RAW files into Lightroom, and do a little tweaking on exposure, but do not do anything in Photoshop. It seems my Canon buddies seem to do a lot with their images in PS. I think that Nikon and Canon take turns getting the upper hand on each other. I do not think you need to switch brands.