Conclusion: I have been using this lens for 6 months regularly. It was purchased as a refurb. Generally, it has functioned very well, mechanically. The focusing motor is good and I don't feel that it is noisy. I would use this lens much more often, except that for more distant subjects the focus is very poor at any aperture setting.
Pros: price is good
Cons: Semi-sharp images, low contrast when zoomed in