Nikon AF D 300mm + 1.4 pro TC idea

[Dana C]

I have heard that buying a Nikon AF D 300mm and coupling with a 1.4 Tamron or Kenko Pro TC which yields 420 mm is a good alternative to the popular zooms from Sigma, (zoom creep), older 80-400 non AFS Nikons and Tamron 200-500's. I am really puzzled and really need some very frank help here. I want to pursue outdoor photography with a focus on wildlife.
Your thoughts would be most welcome

 

[Mr.Photo]

One thing to keep in mind with the TC's is that your maximum aperture will decrease with the TC installed. The Nikon 300mm f/4 will become an f/5.6 lens with the TC installed. This is something to keep in mind if you're shooting in marginal light as you will need to bring the ISO up considerably to get a high enough shutter speed to avoid blurry images.

That being said, I've read of several instances of people using either the Nikon 300mm f/4 (either the AF-D or the newer AF-S version) with a Nikon brand 1.4x TC (expensive) with fantastic results. I own an old AF (screw drive) Tokina 300mm f/4 which is wonderfully sharp, but when I couple it with my Kenko DGX Pro 300 1.4x TC the image quality suffers. If I don't have to crop the image at all it's fine. I can actually get better pictures using just the 300 with no TC, and crop heavily to get what I want.