Hi Mike, I own a Nikkor 28-45/f4.5 and I am quite happy with it. It has a non rotating front, little distortion, quite sharp, but it's rather slow and the zoom range is limited. I have tried the Nikkor 25-50/f4 and decided not to buy it. It is much heavier than the 28-45/f4.5, has a rotating front, and there is noticeable barrow distortion at 25mm and pin cushion distortion at 50mm. However, some people said that the 25-50/f4 is an outstanding lens. I also own a Tokina 24-40/f2.8. This lens is one stop faster than the above Nikkors, not too heavy, well made (all meta), very little distortion, quite sharp, and you can buy it new. If weight and filter size is not a problem, then I would recommend that Tokina 28-70/f2.6 Pro. I don't have this lens, but the reports on it were very good. The new price is about the same as a secondhand Nikkor 25-50/f4. Hope this helps, Sover
