The build quality seems to be very good although the lens is not metal like the Canon
27 August 2014
Summary: This lens was highly rated against the Canon equivalent at half the price. The only complaint was that it was not as rugged as the Canon. I am not a professional and do not subject my equipment to some of the rigors of a working photographer so I don't worry about this.
Summary: I originally used this lens with my Nikon D300 but it really came into its own when used with my D800. The Sigma VR works well and allows me to shoot hand held at lower shutter speeds without having to use a tripod or monopod. The bokeh is pleasing and the lens has a fast and quiet AF.
Summary: I've recently bought this lens, and used it twice. I love the sharpness, and fast focus on the lens. I have several other Sigma lenses and have been pleased with them all. My only reason for not giving this lens 5 stars is because of the crappy tripod collar that came with the lens.
Summary: Upon receipt of this lens I noticed it was heavy and very well built. I connected it to my Sony a77 camera and started taking pictures. Immediately I noticed it focused slowly and was not accurate.
Summary: Obviously the Sony version which is what I clicked review on, should work with these cameras and it does. Very heavy lens. Feels better with the larger body of the a57. Plan to use it on the a55 more because I put a larger strap on that camera that can be placed over one shoulder vs. over the neck.
Summary: I cannot afford an OEM 70-200 f2.8. Almost all Canon / Nikon / Sony ones comes in the $2000 + price tag. This is a great replacement for budget oriented people like me. I have experience shooting with the 70-200 f2.8 L glass from Canon.