The Sigma 50-500 I shot for about 6 months in operation and approximately 2000 images. As a camera, the Nikon D90, the new Nikon D7000, was now in use. At the beginning of the lens had to be returned because the autofocus did not work really reliable. Amazon has organized itself at the weekend with a perfect replacement in advance what you can claim as a very good service. The second lens works to 100%. Compared to the Nikon 70-300 lens this is a hint at the same focal lengths of the imaging quality even better, what justifies the assessment of 5 stars. The heavy weight, zoom shots even in low light are not a major problem because the Bildstabilitsator works great, the weight of 2 kg from the lens supports the "steady hand" automatically. I would buy the lens at any time.
