Summary: Sony's 70-200mm F2.8 G may be based on a 2003 Minolta design, but it's still the best fast telezoom available for Alpha mount users. However it's very pricey in comparison to the Sigma and Tamron alternatives, which are almost as good.
Pros: Excellent image quality on full frame, very good on APS-C, Superb build quality, Fast, silent autofocus with manual override, Well-placed AF stop buttons
Cons: A bit soft wide open at the telephoto end on APS-C, No dust or moisture sealing (which we'd expect in a 'Pro' level lens), Slightly suspect image quality at closest focus (very soft indeed at F2.8), Extremely expensive compared to third party alternatives
Sony 70-200mm f/2.8 SSM G (SAL-70200G) - Full Format Review / Lab Test
24 August 2009
Conclusion: The Sony 70-200mm f/2.8 SSM G can give you very good results on a full format DSLR but it is not a lens without issues. It is certainly sharp - the center image portion has an extremely high quality at all mainstream settings and the borders are generally very good.
Sony 70-200mm f/2.8 SSM G (SAL-70200G) - APS-C Review / Test Report
31 October 2008
Conclusion: The Sony 70-200mm f/2.8 SSM G is a very good lens that certainly deserves its "Gold" class designation. It is very sharp and contrasty across the board and vignetting, lateral CAs as well as distortions are generally very well controlled.