I had the Tokina 300mm 2.8 It's a great lens, well built and very sharp. Great for sports, with it's fast aperture. Be prepared though, it is by no means a compact lens, with the lens hood on it's a monster. Of course it has a tripod collar. I think the filter size was 101mm to give you an idea. I sold mine to a guy that had a Tamron he didn't like. I wouldn't hesitate to buy it over the Nikon for the money.
