I like this lens alot especially for what I paid for it, 175.00 in like new condition. Focus isn't very fast on moving subjects on my D80, but definitely usable for sure. Soft wide open but sharp by 5.6 at 70mm and 8 at 300mm from my experience with it.
These are both wide open examples
These are from the 70-300 af-d ed, Nikon D80

Camera Make: NIKON CORPORATION
Camera Model: NIKON D80
Image Date: 2008:08:24 00:00:02
Flash Used: No
Focal Length: 250.0mm (35mm equivalent: 375mm)
Exposure Time: 0.0031 s (1/320)
Aperture: f/5.3
ISO equiv: 400
White Balance: Auto
Metering Mode: Matrix
Exposure: aperture priority (semi-auto)
Comment: RC2008200vr
Camera Make: NIKON CORPORATION
Camera Model: NIKON D80
Image Date: 2008:08:23 23:50:01
Flash Used: No
Focal Length: 300.0mm (35mm equivalent: 450mm)
Exposure Time: 0.0025 s (1/400)
Aperture: f/5.6
ISO equiv: 400
White Balance: Auto
Metering Mode: Matrix
Exposure: aperture priority (semi-auto)
Comment: RC2008200vr