Sigma 50-500 f/4.0-5.6 Questions.

Basically, I need to know if anyone here has one, and how its working. I am looking for sharpness, focus time, and glass quality, and how it maintains these things all the way up to 500mm. A general overview would be greatly appreciated. Thanks a million.

I have a friend who LOVES this lens. Sharpness is good from the pictures that I've seen. Can't comment on focus time, but I've never read anything on the negative side there. Most of the comments that I've seen from others on this lens have all been positive. Codenamed "BIGMA" due to its size and weight.

I am considering geting this lens, not sure what other lens would compare to this one in price range and quality. I think this lens is going for 1,000$