Brian Schall , Dec 01, 2006; 11:35 a.m.
I'm surprised that the Nikkor ED is the same price as the other two. Are you sure the Nikon lenses is not the 70-300 G, which is more in-line with the other two. The ED's that I've seen are usually 2x the price of the others.
That said, if you can get the ED for about the same price, get it. It is definitely the better lens. I shoot the Nikon 70-300 G on my D50 and have gotten very good results with it. Of course, with the smaller sensor size on the digital camera, you are using the sweet spot in the center of the lens and not the edges of the image circle where the resolution starts to break down.