I would also like to add that I had the Sigma bought as "Nikon version" (for my former Nikon) 18-125mm little over a year ago.
This was me at that time not convince, on the contrary to this "Sony version".
I have the Sigma for my Sony Alpha 37 ordered because the original kit lens (SAL 18-55) a very modest quality offers (at least mine) and I anyway wanted a larger zoom range.
Previously, I had also tested the Tamron Tamron AF 18-200mm 3.5-6.3 XR Di II LD.
This was not bad but igendwie the focus was not so optimal.
So I wanted to try another lens for my Sony and came to the Sigma 18-125mm 3,8-5,6 DC HSM.
Although this is not directly comparable, since it only goes up to 125mm but I felt that as a good "Always top" enough.
A direct comparison of image quality, the Sigma is clearly better!
The Sigma is incredibly sharp, the image sharpness is better over the entire zoom range to some than the Tamron.
The feel and quality (which weighs 490 grams Sigma, Tamron, the 426 grams) feels solid and the Tele moves while wearing not alone out how the Tamron.
The image quality of the Sigma is unbelievably good, almost perfect for my needs as I do without love to a little more focus.
Conclusion:
The Sigma 18-125mm 3,8-5,6 DC HSM is a very good "Always top" (should the price level to keep in mind).
From my clear recommendation!
