One of the old school of telephoto zoom lenses, the Sigma 70-300mm APO Macro lacks an optical stabiliser, which is a big drawback for Canon and Nikon camera users.
Typically solid Sigma build quality and sharpness is good from 70mm up to about 250mm.
Drop off in sharpness at 300mm, lack of image stabilisation and no HSM autofocus.
More than a one-trick pony, the Sigma doubles up as a 0.5x macro lens but, given its relatively poor resolution at the long end of the zoom range, it can't compete with a good macro prime lens. Overall, it's outclassed by Sigma's newer 70-300mm OS lens.