Why is bad: Sigma 17-70mm

1. The lens is quite soft especially on the stated aperture: f/2.8-4. It gets better from f/5.6 to f/8. But then I loose a lot of light!
2. I have problems focusing in auto, especially at 70mm and close range. The focus is haunting and gives irregular focus lock.
3. The maximum magnification is 1:2.7 and minimum focus distance is ridiculously close to the front element, making captures of shy subjects a painful job.
4. And, to make the things even worse, the lens suck dry the battery after only 250 shots, versus 500 with Nikkor 18-55mmVR!
The resulting photos are nothing stellar: so many of you may wander why I have got it! Well, It just better than standard kit lens Nikkor 18-55mm f/3.5-5.6VR, not so heavy and looks like "a million bucks " on my D5000! Awesome, dude!
By SEN.