Going a little old school I picked up a Nikon 300 f4 AF ED-IF lens from www.keh.com. My initial impression of the lens is it's smaller than I imagined it would me. I was expecting the length and weight however it is about the same diameter as an 80-200 f2.8 which is not what I was expecting.
When mounted to the camera it feels pretty well balanced. Its got a good size and weight that wouldn't be too terrible if you had to walk around with it all day. Its comfortable to hold and if you were going to shoot in manual the ring is easy to get to.
The lens overall is sharp and has good color. At f4 it appears to be a little soft but its still very sharp. Once you get to f8 it's very sharp and has a noticeable increase in sharpness. From f8 to f32 there isn't much difference that I can tell in the sharpness. The bokeh at f4 is very smooth and provides very good separation between your subject and the background. The smooth bokeh is similar between f4 and f11, after f11 it starts to taper off but its still nice and smooth up to f32 and still provides decent separation. Color is something I was very impressed with. All the colors were bright, accurate, and stood out when looking at them in Lightroom and where accurate to the actual scene. AF speed and accuracy was very comparable to the 80-200 f2.8 AF. When focusing at different distances the lens snapped right into focus without any hesitation. While I haven't tried using the continuous auto focus I would imagine it would be similar to the 80-200 f2.8 AF.
If you're looking for a 300 f4 and don't have the budget for the AF-S f4 or AF-S f2.8 or aren't planning on using this for a full time sports lens, the 300 f4 AF ED-IF would make a good alternative. In the used market in good condition they are currently running about half the price of a new AF-S f4.
Check out the following photos for a comparison at f4, f8, f11, f16, f22, and f32.